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DNA moleucle

Genetics can’t explain mixed impact of growth hormone therapy

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DNA moleucle

Growth hormone therapy is one of the most common treatments for short stature in children. However, endocrinologists report mixed outcomes, even when children have the same underlying condition as the cause of their short stature. Despite research into a variety of potential causes for this unpredictable response, there is still very little scientific evidence to help physicians predict whether children with short stature who are treated with growth hormone will respond to the treatment or not.

A study published in the Journal of Clinical Endocrinology and Metabolism took up this question with an eye to the genetic factors that might predict response by conducting the first ever genome-wide association study of response to growth hormone.

“Previous disease-specific models have been developed using multiple clinical variables such as parental height, age at treatment start, peak hormone levels and doses, and birth parameters, however, these clinical parameters only partially predict variation in response,” wrote the study authors, including Andrew Dauber, M.D., first author and chief of the division of Endocrinology at Children’s National Hospital. “Our goal was to perform a large-scale genome-wide study to provide a comprehensive assessment of how common genetic variation may play a role in growth hormone response.”

To accomplish this, the study combined five cohorts from across the world to identify 614 individuals for further review. All patients had short stature caused by conditions including growth hormone deficiency, small for gestational age, or idiopathic short stature (no previously identified cause), who received growth hormone as treatment.

Interestingly, the researchers found no overwhelming genetic predictors of response to growth hormone. They did identify a few signals that may potentially play a role in the body’s response to growth hormone but noted those signals will need further exploration. The study also ruled out the idea that genetic predictors of height in the general population might predict response to growth hormone.

“Identifying genetic predictors of how a child with short stature will respond to growth hormone would be an important step forward for clinicians and parents to make informed decisions about the right treatment approach,” says Dr. Dauber. “Though we didn’t find any specific indicators, this large-scale study has allowed us to rule out some previously held assumptions and offers several new avenues to explore.”

The study was conducted in collaboration with Pfizer and Boston Children’s Hospital.

Andrew Dauber

Andrew Dauber, M.D., MMSc, caps off research success with award and reception

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Andrew Dauber

Unfortunately, we’ve been notified that the ENDO2020 conference has been canceled due to concerns of COVID-19. Because of this, we will not be hosting our reception in honor of Andrew Duaber, M.D., on Sunday, March 29.

We hope to see you at a future Endocrinology or Pediatric Endocrinology event.

Children’s National Hospital is incredibly proud of the work Dr. Dauber has done in the endocinology community.

Andrew Dauber, M.D., MMSc, division chief of Endocrinology at Children’s National Hospital, will be awarded the 2020 Richard E. Weitzman Outstanding Early Career Investigator Award at ENDO 2020. The prestigious award will be presented at the annual meeting of the Endocrine Society in recognition of Dauber’s work in understanding the regulation of growth and puberty, and applying innovative genetic technologies to studying pediatric endocrinology. Dauber credits many collaborators throughout the world, as well as the team at Children’s National for the award.

With a five-year grant from the National Institutes of Health (NIH), Dauber and colleagues from the Cincinnati Children’s Hospital Medical Center, Boston Children’s Hospital and the Children’s Hospital of Philadelphia are using electronic health records to identify children who likely have rare genetic growth disorders. Using cutting-edge DNA sequencing technologies, including whole exome sequencing, the researchers are aiming to identify novel genetic causes of severe growth disorders. The first paper describing genetic findings in patients with high IGF-1 levels was published in Hormone Research in Paediatrics in December 2019.

Dauber and researchers at Cincinnati Children’s Hospital Medical Center are exploring how to treat patients with mutations in the PAPPA2 gene. In 2016, the group described the first patients with mutations in this gene who had decreased the bioavailability of IGF-1, stunting their growth and development. In their current phase of research, findings are emphasizing the importance of this gene in regulating IGF-1 bioavailability throughout childhood. The ultimate aim is to create therapies to increase IGF-1 bioavailability, thereby supporting healthy growth and development in children. Their first study to track PAPPA2 and intact IBGBP-3 concentrations throughout childhood was published in the European Journal of Endocrinology in January 2020.

Dauber is particularly interested in studying children with dominantly inherited forms of short stature. Along with collaborators in Cincinnati, he currently has an ongoing treatment trial using growth hormone in patients with Aggrecan gene mutations.  Dauber hopes to announce soon a new clinical trial for children with all forms of dominantly inherited short stature.

Study upon study has shown us that there are many factors that affect an individual’s height and growth. As these studies and the conversation around how to identify and address genomic anomalies become more prevalent, the team at Children’s National is increasingly interested in engaging with other centers around the country. In the coming months, the Children’s National Research & Innovation Campus will open on the grounds of the former Walter Reed Army Medical Center, which will serve as a one-of-a-kind pediatric research and innovation hub. A critical component to this campus is the co-location of Children’s National research with key partners and incubator space.

regional pediatric endocrinology meeting

Regional pediatric endocrinologists gather at Children’s National

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regional pediatric endocrinology meeting

On Nov. 10, 2019, more than 30 pediatric endocrine physicians and nurse practitioners from Washington, D.C., Maryland and Northern Virginia gathered at Children’s National Hospital to discuss the latest in pediatric endocrinology research.

Organized by Paul Kaplowitz, M.D., Professor Emeritus of Pediatrics, this was the third regional pediatric endocrinology meeting since 2012 and the second held at the hospital. “The meetings are a great opportunity for providers to meet regional colleagues who they may communicate with about patients but rarely see face to face,” explains Dr. Kaplowitz.

The providers spent half a day at Children’s National viewing presentations and connecting with their colleagues. Among the presentations was a talk by new Children’s National faculty member Brynn Marks, M.D., MSHPEd, titled, “Medical Education in Diabetes Technologies.”

The presentation highlighted Dr. Marks’ research on how to best teach providers to make optimal use of the information provided by continuous blood glucose monitoring, as well as how to adjust insulin pump settings based on frequent blood glucose testing.

Another notable presentation was by Richard Kahn, Ph.D., recently retired former chief scientific and medical officer at the American Diabetes Association. Dr. Kahn’s talk was titled “Prediabetes: Is it a meaningful diagnosis?”

“This was an excellent talk whose message was that making a diagnosis of ‘prediabetes’ may not be nearly as helpful as we thought, since most patients tests either revert to normal or remain borderline, and there is no treatment or lifestyle change which greatly reduces progression to type 2 diabetes,” says Dr. Kaplowitz.

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Children’s National regional pediatric endocrinology meeting presentations

Welcome from Paul Kaplowitz, M.D., and Children’s National Endocrinology Division Chief Andrew Dauber, M.D.

“Prediabetes: Is it a meaningful diagnosis?”
Richard Kahn, Ph.D., University of North Carolina at Chapel Hill

“Overlapping genetic architecture of Type 2 diabetes and Cystic fibrosis-related diabetes”
Scott Blackman, M.D., Ph.D., Johns Hopkins Medicine

“Pediatric Pituitary Tumors: What we have learned from the NIH cohort”
Christina Tatsi, M.D., Ph.D., National Institutes of Health

“Medical Education in Diabetes Technologies”
Brynn Marks, M.D., MSHPEd, Children’s National Hospital

“A phenotypic female infant with bilateral palpable gonads”
Cortney Bleach, M.D., Walter Reed National Military Medical Center

“Estimating plasma glucose with the FreeStyle Libre Pro CGM in youth: An accuracy analysis”
Miranda Broadney, M.D., MPH, University of Maryland School of Medicine

“Recruiting for research project on “Arginine-Stimulated Copeptin in the diagnosis of central diabetes insipidus”
Chelsi Flippo, M.D., Fellow, National Institutes of Health

Andrew Dauber

Andrew Dauber, M.D., MMSc, awarded prestigious laureate award

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Andrew Dauber

Unfortunately, we’ve been notified that the ENDO2020 conference has been canceled due to concerns of COVID-19. Because of this, we will not be hosting our reception in honor of Andrew Duaber, M.D., on Sunday, March 29.

We hope to see you at a future Endocrinology or Pediatric Endocrinology event.

Children’s National Hospital is incredibly proud of the work Dr. Dauber has done in the endocinology community.

Andrew Dauber, M.D., MMSc, division chief of Endocrinology at Children’s National Hospital, will receive the 2020 Richard E. Weitzman Outstanding Early Career Investigator Award from The Endocrine Society. Given annually, the award was established in 1982 and honors the memory of the late Richard E. Weitzman, who had a brief but outstanding career studying neurohypophyseal hormone and cardiovascular-endocrine physiology – two seminal areas of modern endocrinology.

Dr. Dauber was selected as a recipient for the prestigious award for his contributions to understanding the regulation of growth and puberty, and his success at applying innovative genetic technologies to studying pediatric endocrinology.

“I feel extremely honored and humbled to be the recipient of the Richard E. Weitzman Outstanding Early Career Investigator Award from the Endocrine Society,” says Dr. Dauber. “I am so grateful to my many collaborators throughout the world as well as to my entire research team whose hard work and friendship are the basis for this award. I am excited to continue our work at Children’s National, an institution dedicated to innovation and team science.”

Dr. Dauber joined Children’s National in 2018 and specializes in studying and treating growth disorders. He has published over 75 studies examining genetic clues to endocrine disorders, with a focus on short stature and growth disorders.

The award will be presented at ENDO 2020, The Endocrine Society’s annual meeting, March 28-31, 2020, in San Francisco, California.

nurse checking boy's blood sugar levels

Improving glycemic control in diabetic children

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nurse checking boy's blood sugar levels

A 10-week pilot study at Children’s National Health System integrated weekly caregiver coaching, personalized glucose monitoring and incentives into standard treatment for 25 pediatric patients with type 1 diabetes, lowering A1c by .5%

The life of a type 1 diabetes patient – taking daily insulin shots or wearing an insulin pump, monitoring blood sugar, prioritizing healthful food choices and fitting in daily exercise – can be challenging at age 5 or 15, especially as holidays, field trips and sleepovers can disrupt diabetes care routines, creating challenges with compliance. This is why endocrinologists from Children’s National Health System experimented with using health coaches over a 10-week period to help families navigate care for children with type 1 diabetes.

By assembling a team of diabetes educators, dietitians, social workers, psychologists and health care providers, Fran Cogen, M.D., C.D.E., director of diabetes care at Children’s National, helped pediatric patients with type 1 diabetes manage their glycemic status, or blood-sugar control.

On Saturday, June 8, 2019, Dr. Cogen will share results of the pilot program as poster 1260-P, entitled “A Clinical Care Improvement Pilot Program: Individualized Health Coaching and Use of Incentives for Youth with Type 1 Diabetes and their Caregivers,” at the American Diabetes Association’s 79th Scientific Sessions, which takes place June 7-11 at the Moscone Center in San Francisco.

Dr. Cogen’s study was offered at no cost to caregivers of 179 patients at Children’s National seeking treatment for type 1 diabetes. The pilot program included two components: 1) Weekly phone calls or emails from a health coach to a caregiver with personalized insulin adjustments, based on patient blood sugars submitted through continuous glucose monitoring apps; and 2) Incentives for patients to participate in the program and reach health targets.

Twenty-five participants, ages 4-18, with a mean age of 11.6 and A1c ranges between 8.6 – 10% joined the study. The average A1c was 9.4% at the beginning of the program and dropped by an average of .5% at the end of the trial. Twenty of the 25 participants, 80%, improved A1c levels by .5%. Seventeen participants, 68%, improved A1c levels by more than .5%, while seven participants, 28%, improved A1c levels by more than 1%.

“Chronic disease is like a marathon,” says Dr. Cogen. “You need to have constant reinforcement and coaching to get people to do their best. Sometimes what drives people is to have people on the other end say, ‘Keep it up, you’re doing a good job, keep sending us information so that we can make changes to improve your child’s blood sugar management,’ which gives these new apps and continuous glucose monitoring devices a human touch.”

Instead of waiting three months between appointments to talk about ways a family can make changes to support a child’s insulin control and function, caregivers received feedback from coaches each week. Health coaches benefitted, too: They reported feeling greater empathy for patients, while becoming more engaged in personalizing care plans.

Families who participated received a gift card to a local grocery store, supporting a child’s dietary goals. Children who participated were also entered into an iPad raffle. Improvements in A1c levels generated extra raffle tickets per child, which motivated participants, especially teens.

“These incentives are helpful in order to get kids engaged in their health and in an immediate way,” says Dr. Cogen. “Teenagers aren’t always interested in long-term health outcomes, but they are interested in what’s happening right now. Fluctuating blood sugars can cause depression and problems with learning, while increasing risk for future complications, including eye problems, kidney problems and circulation problems. As health care providers, we know the choices children make today can influence their future health outcomes, which is why we designed this study.”

Moving forward, Dr. Cogen and the endocrinologists at Children’s National would like to study the impact of using this model over several months, especially for high-risk patients, while  asynchronously targeting information to drive behavior change – accommodating the needs of families, while delivering dose-specific recommendations from health care providers.

Dr. Cogen adds, “We’re moving away from office-centric research models and creating interventions where they matter: at home and with families in real time.”

Read more about the study at Healio.com and dLife.

Additional study authors, all of whom work within the division of diabetes and endocrinology at Children’s National, include Lauren Clary, Ph.D., Sue-Ann Airborne, C.D.E., Andrew Dauber, M.D., Meredith Dillon, R.D., L.D.N., C.D.E., Beakel Eshete, B.S.N., R.N., C.D.E., Shaina Hatchell, B.S.N., R.N., Shari Jones, R.N., C.D.E., and Priya Vaidyanathan, M.D.

M and her daughter

Tracing the history of aggrecan gene mutations

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M and her daughter

M takes a photo with her daughter in Washington, where they learned they have an ACAN gene mutation that causes short stature.

On Sunday, April 28, 2019 a team of researchers received the 2019 Human Growth Award at the Pediatric Endocrine Society’s Annual Meeting for their abstract, entitled “Clinical Characterization and Trial of Growth Hormone in Patients with Aggrecan Deficiency: 6 Month Data,” and presented this at the PES Presidential Poster Session.

Eirene Alexadrou, M.D., a fellow at Cincinnati Children’s Hospital Medical Center, accepted the award and honorarium, while ongoing research is underway. This study started in 2017, with the objective of characterizing the phenotypic spectrum and response to a standardized regimen of growth hormone in a small cohort of 10 patients and their families.

In 2017, Andrew Dauber, M.D., MMSc., the division chief of endocrinology at Children’s National Health System, led an international consortium of researchers in publishing a manuscript describing the phenotypic spectrum of 103 individuals – 70 adults and 33 children, including 57 females and 46 males – from 20 families with aggrecan gene (ACAN) mutations.

Dr. Dauber and his colleagues have established that short stature and accelerated bone age is common among people with ACAN mutations. In a review of retrospective data, including patients treated with a variety of growth-promoting therapies at varying doses, the research team found that over the first one, two and three years of treatment, the standard deviation scores (SDS) for height increased by .4, .7 and 1, respectively. The current abstract now describes seven children enrolled in a prospective standardized trial of growth hormone therapy. After six months of treatment, the children have increased their height SDS by an average of 0.46.

Additionally, the researchers are performing an in-depth look at the joint effects, including special MRIs of the knees. They found that two of the children had a problem with their knee cartilage called osteochondritis dissecans. They had not yet presented with clinical symptoms. The researchers hope that early intervention with physical therapy can help prevent significant joint disease in the future.

M and her mother and daughter in Cincinnati

M, her daughter, and M’s mother take a photo in Cincinnati, where they are participating in a clinical trial for aggrecan deficiency.

“Providing growth hormone therapy to children with ACAN gene mutations is relatively new in the field of pediatric endocrinology,” notes Dr. Dauber. “Previously, the assumption was that this was just short stature. We’ll continue to diagnose ACAN mutations in a clinical setting and work with families to reduce the risk of complications, such as joint problems or early-onset arthritis, which may co-occur with this gene mutation.”

As an example, Dr. Dauber met an 8-year-old patient several months ago who presented with symptoms of short stature. The patient is healthy, confident and still growing so her mother wasn’t worried about her but she made the appointment to see if there was an underlying cause to her daughter’s short stature. Her family history revealed clues to an ACAN mutation, which was later confirmed through genetic tests. Her mom, M, stands 4’8; her grandmother is 4’9. Her great grandmother was short and her great, great grandfather was 5’1. Short stature and joint problems run in the family. Once M mentioned she had osteochondritis dissecans and a hip replacement, she provided a textbook case study for carrying the ACAN mutation.

After the appointment, M shared the news with her mother about the possibility of having aggrecan deficiency. After taking genetic tests, M, her mother and M’s daughter learned they all have the ACAN mutation, and enrolled in the study that Dr. Dauber is guiding. Suddenly, it all made sense. After examining family photos, they traced the ACAN mutation back through four generations.

They could tell what relatives had an altered copy of the ACAN gene. M had it, while her two sisters did not. M’s mother was an only child, so she didn’t have aunts or uncles to compare her mother’s height to, but M’s grandmother was short, while her grandmother’s brother was average height. Although her mother’s family was from Germany, she learned that there is no specific ancestry associated with this mutation. It happens by chance and is passed down from a single parent to, on average, half of their children, a form of genetic inheritance called autosomal dominant transmission.

Ms great grandmother and grandfather

M’s great grandfather was noticeably shorter than her great grandmother, who was 5’4.

Through further research, M learned that the ACAN gene provides instructions for producing aggrecan protein, which is essential for bone growth, as well as for the stability of cartilage that lines bones and joints, explaining her recurring joint problems.

She also looked into the future, examining potential risk factors for her daughter: joint pain and bone conditions, which could contribute to arthritis, hip dysplasia and back problems.

The diagnosis now makes it easier for M and her daughter to favor bone-building activities that are easy on the joints, like swimming or water aerobics, instead of gymnastics and weight lifting. After having a hip replacement, M was careful to supplement with calcium and vitamin D. Now, she’ll take the same steps to ensure optimal bone health for her daughter. She’ll work with orthopedic specialists as her daughter grows into her pre-teen and adolescent years, carefully monitoring joint pain – altering activities that are tough on the joints, as necessary.

M let her daughter make a decision about growth hormone therapy, which she decided to try. The benefits of the treatment, increased height, carry inconveniences, such as taking daily shots, but they are sticking with it.

“We’re at the tip of the iceberg with research that explores this gene mutation,” says Dr. Dauber. “We’ll continue to study these families, and more, over time to assess growth patterns and  gene expression, which may reveal other mutations associated with short stature or joint problems, and guide future treatment options. It was a coincidence that this family had the ACAN mutation and scheduled an appointment, while we’re conducting this study. Otherwise, they may not have had an answer since this is fairly new research.”

M and her daughter are happy to be part of this study, which they will participate in for the next few years. M’s mother is also glad to participate. She made a different choice, decades ago, to reject hormone treatment when it was offered to her for undiagnosed short stature, but she’s sharing genetic clues, which may influence treatment options for her granddaughter and for her family’s next generation.

The original study, “Clinical Characterization of Patients with Autosomal Dominant Short Stature due to Aggrecan Muations,” appeared in the Feb. 2017 issue of the Journal of Clinical Endocrinology and Metabolism, and published as an online advance on Nov. 21, 2016.

Thirty-six researchers collaborated on this original paper, which was funded by 16 international health institutes and foundations, including the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health, the Swedish Research Council, the Swedish Governmental Agency for Innovation Systems, the Marianne and Marcus Wallenberg Foundation, the Stockholm County Council, the Swedish Society of Medicine, Byggmastare Olle Engkvist’s Foundation, the Sao Paulo Research Foundation, the Spanish Ministry of Education and Science, the Czech Health Research Council and the Ministry of Health, Czech Republic.

DNA Molecule

Using genomics to solve a 20-year case study

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DNA Molecule

“The advent of different technologies and techniques over the years allowed pieces of her diagnosis to be made – and then brought all together,” says Andrew Dauber, M.D., MMSc.

After 20 years, a patient’s family received an answer to a decades-long genetic mystery. Their daughter had two rare disorders, Angelman syndrome and P450scc deficiency, which was detected after researchers found out she had uniparental disomy, two copies of chromosome 15 from one parent and none from another.

The research paper, entitled “Adrenal Insufficiency, Sex Reversal and Angelman Syndrome due to Uniparental Disomy Unmasking a Mutation in CYP11A1,” was published on March 22, 2018, and recognized as the best novel insight paper published by Hormone Research in Paediatrics in 2018, announced at the Pediatric Endocrine Society’s Annual Meeting in Baltimore on Saturday, April 27, 2019.

By using a variety of genetic tools, including whole-exome sequencing, microarray analyses and in-vitro modeling for gene splicing, the researchers were able to confirm this patient had uniparental disomy, a recessive genetic condition. They learned that after she received two impaired copies of chromosome 15 from her father, this woman developed a hormonal problem that led to adrenal insufficiency and sex reversal. This explained why she physically presented as a female, despite having testes and a Y-chromosome. It also explained other symptoms, including developmental delays and seizures.

“It’s a unique conglomeration of symptoms, manifested by the combination of these two very rare disorders,” says Andrew Dauber, M.D., MMSc., the division chief of endocrinology at Children’s National Health System and a guiding research author of this study. “The advent of different technologies and techniques over the years allowed pieces of her diagnosis to be made – and then brought together, commencing a 20-year diagnostic odyssey.”

For example, each of the conditions this patient has is known and rare: Angelman syndrome affects about one in 10 to 20,000 people in the U.S. Typical symptoms include those observed in this patient: delayed development, intellectual disability, speech impairment and seizures. Side-chain cleavage disorder, which leads to adrenal disorders and sex reversal, is also very rare. In 2005 the chances of survival with a P450scc defect were slim, but since then more than 28 infants have been diagnosed with this gene deficiency, which is required to convert cholesterol to pregnenolone, a hormone in the adrenal gland.

Dr. Dauber notes the chances of this occurring again are highly unlikely. The odds here are one in a gazillion. In this case, one disorder unmasked another, leaving researchers with new insights into the methodology for unraveling ultra-rare genetic disorders or for more common rare conditions.

“Knowing about the gene that caused the adrenal insufficiency and understanding this etiology won’t change medical care for this patient, but it will change the way researchers think about genetic detective work and about combining different technologies,” says Dr. Dauber. “We know that genetic disorders can be complex presentations of different disorders combined. This patient didn’t have one disorder, but three.”

When asked about the significance of the award, Dr. Dauber notes that, “It’s not that other people haven’t recognized this concept before, but this case is a striking example of it. Different technologies will unveil different types of genetic changes, which is why you have to use the right technology or the right technologies in the right combination to piece together the whole picture.”

Ahlee Kim, M.D., the lead study author and a clinical research fellow at Cincinnati Children’s Hospital Medical Center, will receive the award and the honorarium.

Additional study authors include Masanobu Fujimoto, Ph.D., Vivian Hwa, Ph.D., and Philippe Backeljauw, M.D., from Cincinnati Children’s Hospital.

The research was supported by grant K23HD07335, awarded to Dr. Dauber, from the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (NIH). Additional funding included grant 1UL1TR001425 from the NIH’s National Center for Advancing Translational Sciences.

ACC19 attendees from Children's National

ACC.19: A focus on pediatric cardiology

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ACC19 attendees from Children's National

Dr. Gerard Martin, center, accepts an award before delivering the 2019 Dan G. McNamara Keynote lecture at ACC.19.

“Innovation meets tradition,” is how many attendees and journalists described the American College of Cardiology’s 68th Scientific Sessions (ACC.19), which took place March 16-18, 2019 in New Orleans, La.

Gerard Martin, M.D., F.A.A.P., F.A.C.C., F.A.H.A., a pediatric cardiologist and the medical director of Global Services at Children’s National, supported this narrative by referencing both themes in his 2019 Dan G. McNamara keynote lecture, entitled “Improved Outcomes in Congenital Heart Disease through Advocacy and Collaboration.” Dr. Martin highlighted advancements in the field of pediatric cardiology that took place over the past 15 years, while touting modern advancements – such as pulse oximetry screenings for critical congenital heart disease – that were a result of physician-led advocacy and collaboration.

Dr. Martin’s message was to continue to invest in research and technology that leads to medical breakthroughs, but to remember the power of partnerships, such as those formed by the National Pediatric Cardiology Quality Improvement Collaborative. These alliances, which generated shared protocols and infrastructure among health systems, improved interstage mortality rates between surgeries for babies born with hypolastic left heart syndrome.

A dozen cardiologists and clinicians from the Children’s National Heart Institute also participated in CME panel discussions or delivered poster presentations to support future versions of this template, touching on early-stage innovations and multi-institution research collaborations. The themes among Children’s National Heart Institute faculty, presented to a diverse crowd of 12,000-plus professional attendees representing 108 countries, included:

Personalized guidelines:

  • Sarah Clauss, M.D., F.A.C.C., a cardiologist, presented “Unique Pediatric Differences from Adult Cholesterol Guidelines: Lipids and Preventive Cardiology,” before Charles Berul, M.D., division chief of cardiology and co-director of the Children’s National Heart Institute, presented “Unique Pediatric Differences from Adult Guidelines: Arrhythmias in Adults with Congenital Heart Disease,” in a joint symposium with the American Heart Association and the American College of Cardiology.
  • Berul, who specializes in electrophysiology, co-chaired a congenital heart disease pathway session, entitled “Rhythm and Blues: Electrophysiology Progress and Controversies in Congenital Heart Disease,” featuring components of pediatric electrophysiology, including heart block, surgical treatment of arrhythmias and sudden death risk.

Early detection:

  • Anita Krishnan, M.D., associate director of the echocardiography lab, presented “Identifying Socioeconomic and Geographic Barriers to Prenatal Detection of Hypoplastic Left Heart Syndrome and Transposition of the Great Arteries” as a moderated poster in Fetal Cardiology: Quickening Discoveries.
  • Jennifer Romanowicz, M.D., a cardiology fellow, and Russell Cross, M.D., director of cardiac MRI, presented the “Neonatal Supraventricular Tachycardia as a Presentation of Critical Aortic Coarctation” poster in FIT Clinical Decision Making: Congenital Heart Disease 2.
  • Pranava Sinha, M.D., a cardiac surgeon, presented the poster “Neuroprotective Effects of Vitamin D Supplementation in Children with Cyanotic Heart Defects: Insights from a Rodent Hypoxia Model” in Congenital Heart Disease: Therapy 2.

Coordinated care:

  • Ashraf Harahsheh, M.D., F.A.C.C., F.A.A.P., a cardiologist with a focus on hyperlipidemia and preventive cardiology, co-presented an update about BMI quality improvement (Q1) activity from the American College of Cardiology’s Adult Congenital and Pediatric Quality Network – BMI Q1 leadership panel.
  • Niti Dham, M.D., director of the cardio-oncology program, and Deepa Mokshagundam, M.D., cardiology fellow, presented the poster “Cardiac Changes in Pediatric Cancer Survivors” in Heart Failure and Cardiomyopathies: Clinical 3.
  • Nancy Klein, B.S.N., R.N., C.P.N., clinical program coordinator of the Washington Adult Congenital Heart program at Children’s National, presented the poster “Improving Completion of Advanced Directives in Adults with Congenital Heart Disease” in Risks and Rewards in Adult Congenital Heart Disease.

Innovation:

  • Jai Nahar, M.D., a cardiologist, moderated “Future Hub: Augmented Cardiovascular Practitioner: Giving Doctors and Patients a New Voice.” The session focused on technical aspects of artificial intelligence, such as language processing and conversational artificial intelligence, as well as how applications are used in patient-physician interactions.
  • Nahar also participated in a key event on the Heart-to-Heart stage, entitled “Rise of Intelligent Machines: The Potential of Artificial Intelligence in Cardiovascular Care.”

“While I enjoyed the significant representation of Children’s National faculty at the meeting and all of the presentations this year, one research finding that I found particularly compelling was Dr. Krishnan’s poster about geographical disparities in detecting congenital heart disease,” says Dr. Berul. “Her research finds obstetricians providing care to women in the lowest quartile of socioeconomic areas were twice as likely to miss a diagnosis for a critical congenital heart defect during a fetal ultrasound, compared to obstetricians providing care for women in the highest quartiles.”

Dr. Krishnan’s study was the collaborative effort of 21 centers in the United States and Canada, and investigated how socioeconomic and geographic factors affect prenatal detection of hypoplastic left heart syndrome and transposition of the great arteries.

“We studied over 1,800 patients, and chose these diseases because they require early stabilization by a specialized team at a tertiary care center,” says Dr. Krishnan, who led the research in conjunction with the Fetal Heart Society Research Collaborative. “We hope that by understanding what the barriers are, we can reduce disparities in care through education and community-based outreach.”

Elizabeth Estrada

A new type 2 diabetes program leader in a time of change

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Elizabeth Estrada

Elizabeth Estrada, M.D., was struck by the increasing number of children with obesity and type 2 diabetes when she finished her fellowship in 1996. That fascination, along with increasingly alarming statistics about the rise in type 2 diabetes in youth over the past 20 years, steered her to a career focused on pediatric diabetes and metabolism that eventually led her to Children’s National Health System, where she will become the director of the type 2 diabetes program this spring.

Coming most recently from the University of North Carolina, where she served as Chief of the Division of Pediatric Endocrinology and Diabetes, Dr. Estrada will work closely with Children’s National Endocrinology Division Chief Andrew Dauber, M.D., and Diabetes Services Director Fran Cogen, M.D., to create a multidisciplinary type 2 diabetes care structure that she has seen success with throughout her career.

“Children with type 2 diabetes have very different needs than children with type 1,” Dr. Estrada explains. “They need more nutrition, more social work, and psychological support.”

Children’s National presents Dr. Estrada with a unique opportunity at a time when the field of care and treatment options for children with type 2 diabetes is expanding. She aims to develop a comprehensive, multidisciplinary program integrating the established Children’s National obesity program with the nationally-ranked endocrinology and diabetes team, which has a strong foundation in providing psychological support to families, which is part of a larger toolkit at Children’s National to help families manage a diabetes diagnosis.

The obesity program at Children’s National emphasizes personalized clinical care and education to prevent and reduce the prevalence of obesity, incorporating multiple aspects of medical and surgical care for obese children and adolescents through the Improving Diet, Energy and Activity for Life (IDEAL) clinic and the bariatric surgery program. The IDEAL clinic helps children with dietary counseling, health education classes, physical activity and weight-management techniques, as well as psychosocial support to help children reach and maintain a healthy weight.

One of the first children’s hospitals to be accredited by the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP®) and the only hospital in the area to be accredited to perform bariatric surgery on adolescents, the bariatric surgery program at Children’s National is directed by Evan Nadler, M.D., who has been safely performing surgeries for nearly 15 years.

The American Diabetes Association (ADA) recently published updates to the “Standards of Medical Care in Diabetes,” which provides research-based practice recommendations for children and adolescents with type 2 diabetes, including metabolic surgery as a treatment recommendation, stating:

The results of weight-loss and lifestyle interventions for obesity in children and adolescents have been disappointing, and no effective and safe pharmacologic intervention is available or approved by the U.S. Food and Drug Administration in youth. Over the last decade, weight-loss surgery has been increasingly performed in adolescents with obesity. Small retrospective analyses and a recent prospective multicenter nonrandomized study suggest that bariatric or metabolic surgery may have benefits in obese adolescents with type 2 diabetes similar to those observed in adults.

The recommendations further stipulate that metabolic surgery should only be considered under certain circumstances, including for those adolescents with T2D who are markedly obsess (BMI > 35 kg/m2) and who have uncontrolled glycemia and/or serious comorbidities despite lifestyle and pharmacologic intervention, and it should only be performed by an experienced surgeon working as part of a well-organized and engaged multidiscipinary team.

Working closely with Dr. Nadler and the obesity team will be a hallmark of Dr. Estrada’s role.

Her goal is to organize a clinic that not only provides clinical care and surgical options, but also includes research and provides medical education and training to medical students, residents and fellows. Dr. Estrada’s own research has focused on insulin resistance, one of the underlying problems in type 2 diabetes.

“There are several clinical trials currently exploring the efficacy and safety of medications for type 2 diabetes in children, something that is incredibly important since Metformin and insulin are the only approved options at this point,” Estrada says. “It is imperative that we bring research to Children’s National as a complement to the existing programs and to continue providing the highest level of care for these patients.”

The Division of Diabetes and Endocrinology works with the National Institutes of Health, conducts independent research and received support from the Washington Nationals Dream Foundation for its diabetes program, the largest pediatric diabetes program in the region, which provides community education and counsels 1,800 pediatric patients each year.

Test tube that says IGF-1 test

A new algorithm: Using genomics and EHR to detect severe growth disorders

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Test tube that says IGF-1 test

Andrew Dauber, M.D., MMSc., a pediatric endocrinologist and the chief of endocrinology at Children’s National, guided research presented at ENDO 2019, the Endocrine Society’s annual meeting, enabling clinicians and researchers to understand the genetic underpinnings of certain pediatric growth disorders, while using electronic health record (EHR) algorithms to screen for presenting symptoms in the exam room. In some cases, this prompts further genetic testing and shortens the diagnostic odyssey for pediatric growth disorders – such as Turner syndrome.

Here is a summary of the research findings, delivered as two oral abstracts and a poster session.

ABSTRACT 1: Presented on Saturday, March 23, at 12:30 p.m. CST

Healthy childhood growth cohort provides insight into PAPPA2 and IGF-1 relationship, revealing a new level of complexity to the biology of growth with implications for the study and treatment of severe growth disorders

Program: Growth, puberty, and insulin action and resistance

Session OR07-5: A Cross-Sectional Study of IGF-I Bioavailability through Childhood: Associations with PAPP-A2 and Anthropometric Data

Background: Insulin-like growth factor 1 (IGF-1) is a hormone essential for human growth and is often bound to IGFBP-3, an IGF binding protein. Pregnancy Associated Plasma Protein-A2 (PAPP-A2) cleaves intact IGFBP-3, freeing IGF-1 to support normal growth functions. This is the first study, led by Dr. Andrew Dauber with collaborators from Cincinnati Children’s Hospital Medical Center, to track PAPP-A2 and intact IGFBP-3 concentrations throughout childhood. The research team studied 838 healthy children, ages 3-18, in the Cincinnati Genomic Control Cohort, to better understand patterns of growth and development by examining the relationship between PAPPA2 and IGF-1 bioavailability.

Study results: Free IGF-1 increased with age. PAPP-A2, a positive modulator of IGF-1 bioavailablity, decreased with age, which surprised the researchers, and is not positively associated with absolute levels of free IGF-1. However, higher levels of PAPP-A2 cleave IGFBP-3 resulting in lower levels of intact IGFBP-3, and consequently, increasing the percentage of free to total IGF-1. This demonstrates that PAPP-A2 is a key regulator of IGF-1 bioavailability on a population-wide scale.

Impact: This research may help endocrinologists create unique, targeted treatment for children with PAPPA2 mutations and could help stratify patients with potential risk factors, such as IGF-1 resistance due to increased binding of IGF-1, associated with severe growth and height disorders. See adjoining study below.

Watch: Video interview with Dr. Dauber

ABSTRACT 2: Presented on Saturday, March 23, at 12:45 p.m. CST

Electronic health records can alert physicians to patients who could benefit from genetic testing to identify severe growth disorders

Program: Growth, puberty, and insulin action and resistance

Session OR07-6: Integrating Targeted Bioinformatic Searches of the Electronic Health Records and Genomic Testing Identifies a Molecular Diagnosis in Three Patients with Undiagnosed Short Stature

Background: Despite referrals to pediatric endocrinologists and extensive hormonal analysis, children with short stature due to a genetic cause, may not receive a diagnosis. Electronic health records may help identify patients – based on associated phenotypes and clinical parameters – who could benefit from genetic testing.

Study results: Researchers from three children’s hospitals – Boston Children’s Hospital, Children’s Hospital of Philadelphia and Cincinnati Children’s Hospital Medical Center – gathered data, starting small, with a known variable, or phenotype, associated with severe growth disorders: insulin-like growth factor 1 (IGF-1) resistance. A targeted bioinformatics search of electronic health records led the team to identify 39 eligible patients out of 234 candidates who met the criteria for a possible genetic-linked growth disorder. Participants were included if their height fell below two standard deviations for age and sex and if their IGF-1 levels rose above the 90th percentile. Patients who had a chronic illness, an underlying genetic condition or precocious puberty were excluded. Whole-exome sequencing (WES) was performed on DNA extracted from willing participants, including 10 patients and their immediate family members. The research team identified new genetic causes in three out of 10 patients with severe growth disorders, who were previously missed as having a genetic-linked growth disorder.

Note: Two patients had two novel IGF1R gene variants; a third had a novel CHD2 variant (p. Val540Phe). The two patients with IGF1R variants had a maternally inherited single amino acid deletion (p.Thr28del) and a novel missense variant (p. Val1013Phe).

Impact: Similar EHR algorithms can be replicated to identify pediatric patients at risk for or thought to have other genetic disorders, while expanding genetic research and improving patient care.

Watch: Video interview with Dr. Dauber

POSTER: Presented on Monday, March 25, at 1 p.m. CST

Electronic health record alerts could help detect Turner syndrome, shorten diagnostic odyssey for girls born with a missing or partially-deleted X chromosome

Program: Session P54. Pediatric puberty, ovarian function, transgender medicine and obesity

Poster Board #MON-249: Algorithm-Driven Electronic Health Record Notification Enhances the Detection of Turner Syndrome

Background: Turner syndrome (TS) results from a complete or partial loss of the second X chromosome and affects about one in every 2,500 female births. TS is common in females with unexplained short stature, but the diagnosis is often not made until late childhood (8-9 years), leading to delays in treatment and screening for comorbidities, such as heart conditions, chronic ear infections, vision problems and challenges with non-verbal learning. Using electronic health record (EHR) alarms can help clinicians screen for and diagnose TS patients earlier in life.

Study results: Researchers from Cincinnati Children’s Hospital Medical Center searched EHRs for female patients with idiopathic short stature who met the team’s selection criteria: Their height fell below two standard deviations from the mean for age as well as one standard deviation below the mid-parental height, had a BMI greater than 5 percent and did not have a chronic illness. The search produced 189 patients who met the diagnostic criteria, 72 of whom had not received prior genetic testing. Out of genetic samples available, 37 were compatible for a microarray analysis – which helped the team identify two cases of TS and a third chromosomal abnormality, all of which were missed by routine clinical evaluation.

Impact: DNA samples may not be available for all patients, but clinicians and researchers can identify and integrate tools into EHR’s – creating their own algorithms. An example includes setting up alerts for specific growth parameters, which helps identify and screen patients for TS.

The abstracts Dr. Dauber and his team discuss at ENDO 2019 support ongoing research, including a partnership among four leading children’s hospitals – Children’s National Health System, Boston Children’s Hospital, Children’s Hospital of Philadelphia and Cincinnati Children’s Medical Center – funded by an R01 grant to study how electronic health records can detect and identify novel markers of severe growth disorders.

The researchers hope their findings will also identify and help screen for comorbidities associated with atypical growth patterns, supporting multidisciplinary treatment throughout a child’s life. The study started in August 2018 and includes three sets of unique diagnostic criteria and will analyze WES from dozens of patients over five years.

Read more about Dr. Dauber’s research presented at ENDO 2019 in Endocrine Today and watch his video commentary with Medscape.

DNA

International collaboration discovers new cause for dwarfism

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DNA

An international collaboration resulted in the identification of a new cause of dwarfism: mutations in a gene known as DNMT3A.

Beyond diabetes, short stature is the most common reason for children in the U.S. to visit an endocrinologist. For the vast majority of children with short stature, the cause remains unknown – even though many of these conditions stem from an as-yet unidentified genetic cause, says Andrew Dauber, M.D., M.M.Sc., division chief of Endocrinology at Children’s National Health System.

“Parents are concerned about why their child isn’t growing and if there are other complications or health problems they’ll need to watch out for,” he says. “Without a diagnosis, it’s very hard to answer those questions.”

Dauber’s research focuses on using cutting-edge genetic techniques to unravel the minute differences in DNA that limit growth. This research recently led him and his colleagues to identify a new cause of dwarfism: mutations in a gene known as DNMT3A. The discovery, which the team published in the January 2019 Nature Genetics, didn’t happen in isolation – it required a rich collaboration of labs spread across the world in Scotland, Spain, France and New Zealand, in addition to Dauber’s lab in the U.S.

The journey that brought Dauber into this group effort got its start with a young patient in Spain. The boy, then four years old, was at less than 0.1 percentile on the growth curve for height with a very small head circumference and severe developmental delays. This condition, known as microcephalic dwarfism, is incredibly rare and could stem from one of several different genetic causes. But his doctors didn’t know the reason for this child’s specific syndrome.

To better understand this condition, Dauber used a technique known as whole exome sequencing, a method that sequences all the protein-coding regions in an individual’s entire genome. He found a mutation in DNMT3A – a change known as a de novo missense mutation, meaning that the mutation happened in a single letter of the boy’s genetic code in a way that hadn’t been inherited from his parents. But although this mutation was clear, its meaning wasn’t. The only clue that Dauber had as to DNMT3A’s function was that he’d read about overgrowth syndromes in which the function of this gene is lost, leading to large individuals with large heads, the exact opposite of this patient’s condition.

To gather more information, Dauber reached out to Andrew Jackson, Ph.D., a researcher who studies human genes for growth at the University of Edinburgh in Scotland. Coincidentally, Jackson had already started studying this gene after two patients with a shared mutation in a neighboring letter in the genetic code – who also had short stature and other related problems – were referred to him.

Dauber and his colleagues sent the results from their genetic analysis back across the Atlantic to Jackson’s Edinburgh lab, and the doctors from Spain sent more information to Jackson’s lab, including the patient’s clinical information, blood samples and skin biopsy samples. Then the whole team of collaborators from around the globe set to work to discover the processes influencing short stature in each of these three patients.

Their results showed that these mutations appear to cause a gain of function in DNMT3A. This gene codes for a type of enzyme known as a methyltransferse, which places methyl groups on other genes and on the protein spools called histones that DNA wraps around. Each of these functions changes how cells read the instructions encoded in DNA. While the mutations that cause the overgrowth syndromes appear to allow stem cells to keep dividing long past when they should taper off and differentiate into different cell types – both normal processes in development – the gain of function that appears to be happening in these three patients prompts the opposite situation: Stem cells that should be dividing for a long time during development stop dividing and differentiate earlier, leading to smaller individuals with far fewer cells overall.

The researchers confirmed their findings by inserting one of the gain-of-function human DNMT3A mutations into a mouse, leading to short animals with small heads.

Eventually, says Dauber, these findings could help lead to new treatments for this and other types of dwarfism that act on these genetic pathways and steer them toward normal growth. These and other scientific discoveries hinge on the type of international collaboration that he and his colleagues engaged in here, he adds – particularly for the types of rare genetic syndromes that affect the patients that he and his colleagues study. With only a handful of individuals carrying mutations in certain genes, it’s increasingly necessary to combine the power of many labs to better understand the effects of these differences and how doctors might eventually intervene.

“The expertise for all aspects of any single research project is rarely centered in one institution, one city, or even one country,” Dauber says. “Often, you really need to reach out to people with different areas of expertise around the world to make these types of new discoveries that can have pivotal impacts on human health.”

Andrew Dauber at his computer doing a Reddit AMA

Thirteen questions for a pediatric endocrinologist

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Andrew Dauber at his computer doing a Reddit AMA

Andrew Dauber, M.D., hosts an AMA chat with Reddit’s science community and offers feedback about height, growth disorders and pediatric endocrinology.

Andrew Dauber, M.D., MMSc., the division chief of endocrinology at Children’s National, spoke about epigenetics – how genes are expressed – and about all things related to pediatric endocrinology in a recent Ask Me Anything (AMA) chat with Reddit’s science community.

We’ve selected highlights from several questions Dr. Dauber received. You can view the full AMA discussion on Reddit.

Q1: What will the future of type 1 diabetes treatment look like?

As a pediatric endocrinologist, Dr. Dauber sees a lot of patients with type 1 diabetes. He predicts technology will pave the way for advancements with continuous glucose monitoring and encourage a ‘real-time’ interaction between patients and providers:

“I anticipate that within a few years, everyone will have access to continuous glucose monitoring technology and that these will be seamlessly connected to insulin pumps or artificial pancreas technologies,” types Dr. Dauber in response to the first AMA question. “I also think there will be more virtual interaction between medical providers and patients with doctors and nurses reviewing blood sugar data in the cloud.”

Q2: What height range is considered normal for a growing child? What is the difference between short stature and a height problem?

The Centers for Disease Control and Prevention has a growth chart, which shows ‘normal’ ranges, based on statistical definitions of height in the general population.

“The truth is that I know plenty of people who have heights below the ‘normal’ population, and they don’t think they have a problem at all,” says Dr. Dauber. “From a genetics point of view, the question can be reframed: When do we call a genetic variant a ‘mutation’ versus a rare variant in the population? For example: If there is a genetic change that 1 in a 1,000 people have that causes you to be 2 inches shorter – is that a problem? Is that a disease?”

“From a clinical perspective, I tend to have a discussion with my patients and their families and ask them how their stature is affecting their lives and whether changing that would really make a meaningful difference,” adds Dr. Dauber. “I believe that this is a very personal decision but people need to be realistic about expected outcomes.”

Q3: What are your favorite case studies about atypical growth or height patterns?

Dr. Dauber references two case studies about growth and puberty:

The growth case study refers to the PAPPA2 gene, which was particularly meaningful for Dr. Dauber since he got to know the family and was able to provide answers to a previously undiagnosed medical mystery about short stature. This research is also opening future studies and analysis about the regulation of IGF-1 bioavailability.

The puberty case study looks at the opposite end of growth and development: precocious puberty. In this case an inherited MKRN3 gene mutation resulted in new insight about the regulation of pubertal timing: Deficiency of MKRN3 caused central precocious puberty in humans. Girls who had inherited the mutated genes from their father (an imprint gene) started to develop breasts before age 6. The results were published in The New England Journal of Medicine.

Q4: What are the differences with consistent and inconsistent growth disorders? Could one arm or leg experience accelerated or stunted growth?

“Most genetic disorders that affect growth will have a uniform effect throughout the body as they are likely to affect all aspects of the skeleton,” says Dr. Dauber. “That being said, there are some notable exceptions such as Russell-Silver syndrome which presents with body asymmetry. There are also somatic mutations (mutations which are just present in some cells in the body) that can lead to segmental areas of overgrowth leading to asymmetry.”

Q5: Can you predict height and growth by looking at genetic factors? What are your thoughts about polygenic risk scores?

“Polygenic risk scores will probably play more of a role in the future to help determine risk of a certain disease,” says Dr. Dauber. “Right now, for most conditions, the risk score does not explain a substantial enough fraction of the variation to help with prediction.”

Dr. Dauber discusses how this works for height, a highly hereditable trait, in The Journal for Clinical Endocrinology and Metabolism. In the review, Dr. Dauber and the study co-authors note that individuals with extreme heights are more likely to have abnormal stature as a result of a severe mutation that causes a growth disorder. For these individuals, whole exome sequencing may reveal gene mutations.

However, the study authors note that for now, the role of these technologies in individuals with extreme stature but without any syndromic features has not been rigorously and systematically explored. (Dr. Dauber and a team of endocrinologists from leading children’s hospitals are currently using electronic health records to study and track these types of genetic clues over time.)

Q6: The general public is excited about genetics and ongoing research, especially with consumer applications – such as genetic tests, including 23andMe. What misconceptions about genetics do people have? What ethical concerns do geneticists share right now?

“Many people think that genetics is completely deterministic,” says Dr. Dauber. “In reality, most genetic variants influence a person’s predisposition toward a trait or disease but don’t actually determine the outcome. Also, the genetic sequence itself is just the first step. Epigenetics, gene regulation, and gene-environment interactions are all important and we are just scratching the surface of understanding these areas.”

“I think that people engaged in genetics research are very interested in the ethical questions,” adds Dr. Dauber. “The problem is that technology is advancing at such a rapid pace, that often consumers are using technologies in ways that we haven’t yet had time to figure out the ethics for. The medical community is often playing catch up.”

Q7: Aside from using gene modifications to cure diseases, where or when should we draw the line in terms of enhancement?

“I think genetic modification for enhancement is a very dangerous slippery slope that we should avoid,” says Dr. Dauber. “We really don’t know the full effect of many genes and by enhancing them, we could be causing lots of problems that we can’t anticipate. There is a reason that evolution is a slow process that happens over millions of years. I think we need to start with the most devastating diseases and try to cure those first.”

Q8: Would it be ethical to use CRISPR on the genes for short stature to produce tall offspring if the risks are sufficiently small? This would be similar to what Dr. He did, but without the ethical violations.

“This is a fascinating question and it will become more of an issue over time,” says Dr. Dauber. “Where do we draw the line between fixing, preventing disease and enhancing physical function? Personally, I think using genome editing to promote height is a terrible idea. Our current perception that taller height is more desirable is a social construct and varies by culture. This idea also changes over time.”

Q9: Overall, how does this fit into meeting unmet medical needs?

“I would be very wary about trying to design our children’s physical features,” Dr. Dauber notes. “We need to figure out as a society what diseases are sufficiently problematic that we feel comfortable trying to eliminate them via genome editing.”

Q10: How many genes control acromegaly? Is it possible (in theory) to Top of Formselect them just to gain the positive effects of gigantism without the health risks?

Dr. Dauber explains that acromegaly, a condition often referred to as gigantism, is caused by a growth hormone-producing tumor. There are a few genes known to cause these tumors, including the AIP, and there was recently a genetic cause of X-linked gigantism, which was published in The New England Journal of Medicine.

“This basic idea is a good one,” notes Dr. Dauber. “We can find genes that when mutated can cause tall stature – and then try to manipulate those pathways. A great example is the NPR2 gene, which when mutated can cause short or tall stature. This pathway is being targeted for therapeutics related to achondroplasia.”

The National Institutes of Health (NIH) refers to achondroplasia as ‘short-limbed dwarfism,’ which results in an average-sized trunk with short limbs, especially arms and legs, due to a lack of cartilage turning into bone. The average height of an adult male with achondroplasia is 4 feet, 4 inches, while the average height of adult females with achondroplasia is less than 4 feet, 1 inch. In this case, manipulating growth pathways may help alleviate health problems associated with achondroplasia: lack of mobility or range of motion, an enlarged head, apnea, ear infections and spinal stenosis, or a compression or pinching of the spinal cord.

Q11: Give us a history lesson. Why are there variations of height within populations, such as Asia and Latin America?

“The average height in a population is due to the influence of literally thousands of common genetic variants,” says Dr. Dauber. “These population differences have evolved over thousands of years due to a combination of migration and selection. There is a well-known difference in the genetic makeup of various populations which likely underlies the differences across the globe. There are even differences within Europe.”

Q12: Are there examples of pseudoscience or theories about growth, such as recommendations to eat a certain food instead of taking growth hormones to correct for a growth disorder, which runs contrary to scientific evidence, that drive you crazy?

“I don’t really get bothered by crazy theories, but it is upsetting when patients and their families get swindled into spending their money on therapies that aren’t truly effective,” says Dr. Dauber. “People ask me all the time if a certain food or exercise can make their child taller. The bottom line is that in a well-nourished (and healthy) child, there is no magical food that is going to make them tall.”

Q13: According to almost every theory of how life evolved on Earth, from religion to evolution, we all have one common ancestor. In theory doesn’t that make us all cousins?

“Yes, just very distant ones,” says Dr. Dauber. “People always point out the vast number of differences between races but in fact we are all more than 99.9 percent identical on a genetic level.”

Stay on top of the latest pediatric endocrinology news by following @EndoDocDauber and @ChildrensHealth on Twitter: #GrowUpStronger.

Test tube that says IGF-1 test

PAPPA2: A genetic mystery

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Test tube that says IGF-1 test

What would happen if you suddenly stopped growing at age 12 or 13?

Solving genetic growth mysteries and scheduling regular appointments with pediatric endocrinologists is atypical for most parents and pediatricians.

However, for children with growth disorders – a classification that typically describes children below the third or above the 97th percentile of growth charts for their age – receiving a diagnosis is half the battle to reaching average height. Understanding and creating treatment for a growth disorder, which could stem from an underlying medical illness, a genetic mutation or a problem with endocrine function, such as the production or action of growth hormone, is often the next step.

For Andrew Dauber, M.D., MMSc., the chief of endocrinology at Children’s National Health System, a third step is to use these clues to create larger datasets and blueprints to identify risk factors for rare growth disorders. By understanding genetic markers of growth disorders, endocrinologists can identify solutions and create plans for multidisciplinary care to help children reach developmental milestones and receive coordinated care throughout their lifespan.

A case study that Dauber and his research team continue to explore is how to correct for mutations in the PAPPA2 gene, which regulates human growth by releasing a key growth factor called insulin-like growth factor 1 (IGF-1). Dauber and his colleagues recently described a mutation in PAPPA2, observed in two families with multiple children affected with significant short stature. He found that this mutation decreased the bioavailability of IGF-1, stunting the growth and development of the children who carry this mutation.

While the PAPPA2 mutation is rare, endocrinologists, like Dauber, who understand its function and dysregulation can create solutions to support IGF-1 bioavailability, thereby supporting healthy growth and development in children.

Understanding barriers to IGF-1 function can also help researchers gain insight into the relationship between PAPPA2, levels of circulating insulin in the body, which could cause insulin resistance, and other growth hormones. For now, Dauber and his research team are exploring how to use PAPPA2 to increase IGF-1 in circulation among people with height disorders in the hopes of improving their growth.

“The population of children who have PAPPA2 mutations is small and we’re finding out that two children could respond to the same treatment in different ways,” says Dauber. “One medication could work modestly in one child and support short growth spurts, such as growing by 5 or 6 cm a year. It could also create undesirable side effects, such as headaches and migraines in another, and render it ineffective. However, the clues we walk away with enable us to test new solutions, and confirm or dissolve our hunches, about what may be preventing the bioactive release of essential growth hormones.”

To generate controls for healthy patterns of growth and development, Dauber and his research team are analyzing the relationship between PAPPA2, STC2 and IGFBP-3 concentrations among 838 relatively healthy pediatric participants, ages 3-18, with traditional growth patterns.

They are studying PAPPA2, STC2 and intact IGFBP-3 concentrations throughout childhood and the researchers are already surprised to find PAPPA2, a positive modulator of growth and IGF- bioavailability, decreased with age, while STC2, a negative modulator and traditional growth inhibitor, increased with age.

“As pediatric endocrinology researchers and clinicians, we’re looking at the pathology of traditional growth patterns and growth disorders with an open mind,” says Dr. Dauber. “These data sets are invaluable as they confirm or challenge our theories, which enable us to create and test new forms of personalized treatments. We’ll continue to share this knowledge, which informs other researchers and accelerates the field of pediatric endocrinology.”

This research was presented at the annual meeting of the European Society of Pediatric Endocrinology in Athens on Sept. 28, 2018.

Dauber and his research team will present their findings at endocrinology conferences and grand rounds throughout 2018 and 2019.

To view Dr. Dauber’s most recent research and pediatric endocrinology reviews, visit PubMed.

Andrew Dauber

Growth disorder study starts by analyzing DNA

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The National Institutes of Health has awarded Andrew Dauber, M.D., MMSc, the chief of endocrinology at Children’s National Health System, a five-year grant that will allow four pediatric health systems to compile and study clinical and genetic markers of severe pediatric growth disorders.

The study will use the electronic health records of large health systems combined with DNA samples from dozens of children, with the goal of enabling endocrinologists to detect children with previously undiagnosed severe genetic growth disorders.

“If you’re a pediatrician treating an 8-year-old patient who has stopped growing, the first thing you’ll want to do is determine the underlying cause, which could be due to many factors including a genetic mutation,” says Dr. Dauber. “There are many reasons why children grow poorly and it is often very difficult to figure out what is causing the problem. However, the various causes may be treated quite differently and may alert us to other medical issues that we need to watch out for. We need to be able to identify clues from the patient’s clinical presentation that may point us to the right diagnosis.”

Dr. Dauber and endocrinology researchers from Children’s National Health System, Cincinnati Children’s Hospital Medical Center, Boston Children’s Hospital and The Children’s Hospital of Philadelphia will use electronic health records to identify children who likely have rare genetic growth disorders. They will then use cutting-edge DNA sequencing technologies, whole exome sequences, to identify novel genetic causes of severe growth disorders. Patients with growth hormone resistance, resistance to insulin-like growth factor 1 (IGF-I) and severe short stature inherited from a single parent will be recruited for the initial phases of the study.

“It’s rare to find patients meeting criteria for each of these subgroups, which is why it’s critical to work collaboratively across institutions,” says Dr. Dauber. “This type of genetic sorting and sharing brings us closer to identifying new markers for severe or treatment-resistant growth disorders, which will help alert pediatricians and parents to potential risks earlier on in a child’s life.”

In addition to assessing genetic markers for short stature, the endocrinologists will conduct pilot studies of targeted interventions, such as IGF-I therapy in patients with mutations in the growth hormone pathway, based on these genetic underpinnings.

“Ideally, by identifying markers of severe growth disorders first, we’ll be able to provide targeted treatments and therapies later on to help patients throughout their lifespan,” adds Dr. Dauber.

Typical treatments for atypical growth patterns include growth hormone or less commonly insulin-like growth factor, or IGF-1, for short stature and hormone-inhibiting treatments for precocious puberty.

The multicenter clinical trial is funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), under grant Ro1HD093622, and runs through June 30, 2023.

Andrew Dauber

Andrew Dauber, M.D., joins Children’s National as Chief of Endocrinology

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Andrew Dauber

“Researchers, clinicians and medical trainees are pressed for time,” says Andrew Dauber, M.D. “Merging these three arenas into a joint infrastructure powers institutional collaboration and fuels transformative, cutting-edge care.”

Imagine an endocrinology division staffed with endowed researchers, clinicians and specialists, that serves as an engine of innovation, making it easy for pediatricians to make the right referrals, based on the best research, to endocrinologists who can provide families with cutting-edge care.

Andrew Dauber, M.D., MMSc, the new chief of endocrinology at Children’s National, is turning this dream into a reality. Over the next few years, Dr. Dauber will work with a nationally-ranked endocrinology and diabetes center to build a clinical endocrinology research program, housing specialty clinics for Turner’s syndrome, thyroid care and growth disorders, amongst others.

“Researchers, clinicians and medical trainees are pressed for time,” notes Dr. Dauber. “Merging these three arenas into a joint infrastructure powers institutional collaboration and fuels transformative, cutting-edge care.”

To put his real-life hypothesis of providing an engine for innovation into practice, Dr. Dauber led the interdisciplinary growth center at Cincinnati Children’s Hospital Medical Center and organized a Genomics First for Undiagnosed Diseases Program to study genetic clues for undiagnosed diseases. At Boston Children’s Hospital, he was the assistant medical director for the clinical research unit and held academic appointments with Harvard Medical School.

Dr. Dauber finds it’s critically important to merge clinical practice with research and education. He received his medical degree and a Master’s of Medical Sciences in Clinical Investigation from Harvard Medical School. He has published more than 65 studies examining genetic clues to endocrine disorders, with a focus on short stature and growth disorders.

Dr. Dauber conducted the majority of his research – ranging from studying genetic clues for rare growth disorders and causes of precocious puberty to genes that regulate the bioavailability of IGF1, insulin-like growth factor – while counseling patients, advising students and fellows, managing grants, reviewing studies and speaking at international pediatric endocrinology conferences.

He’s harnessing this data by combining genomic insights with electronic health records and patient registries. While some of this information can be used immediately to identify a high-risk patient, other conditions may take years to understand. Dr. Dauber views this as an investment in the future of pediatric endocrinology.

“I’m excited to join Children’s National and to work in Washington, where we can power our city and the nation with premier partnerships and collaboration,” adds Dr. Dauber. “In addition to using genetic clues to investigate growth disorders, we’re just as enthusiastic about investing in and expanding access to youth-focused diabetes education and care.”

The Division of Diabetes and Endocrinology works with the National Institutes of Health, conducts independent research and received support from the Washington Nationals Dream Foundation for its diabetes program, the largest pediatric diabetes program in the region, which provides community education and counsels 1,800 pediatric patients each year.