Germline microsatellite genotypes differentiate children with medulloblastoma
Brian Rood, M.D., oncologist and medical director at the Brain Tumor Institute, and Harold “Skip” Garner, Ph.D., associate vice provost for research development at Edward Via College of Osteopathic Medicine, published a report in the Society for Neuro-Oncology’s Neuro-Oncology Journal about using a novel approach to identify specific markers in germline (non-tumor) DNA called microsatellites that can differentiate children who have the brain tumor medulloblastoma (MB) from those who don’t.
“Ultimately, the best way to save children from brain tumors and prevent them from bearing long-term side effects from treatment is to prevent those tumors from occurring in the first place,” says Dr. Rood. “New advancements hold the potential to finally realize the dream of cancer prevention, but we must first identify those children at-risk.”
While analyzing germline sequencing data from a training set of 120 MB subjects and 425 controls, the doctors identified 139 individual microsatellites whose genotypes differ significantly between the groups. Using a genetic algorithm, they were able to construct a subset of 43 microsatellites that distinguish MB subjects from controls with a sensitivity and specificity of 92% and 88% respectively.
“We made discoveries in an untapped part of the human genome, enabled by unique bioinformatics data mining approaches combined with clinical insight,” said Dr. Garner. “Our findings establish new genomic directions that can lead to high accuracy diagnostics for predicting susceptibility to medulloblastoma.”
What the doctors discovered and demonstrated in the study was that MB-specific germline microsatellite variations mark those at risk for MB development and suggest that other mechanisms of cancer predisposition beyond heritable mutations exist for MB.
“This work is the first to demonstrate the ability of specific DNA sequences to differentiate children with cancer from their healthy counterparts,” added Dr. Rood.
Contributing Authors to this research study included: Brian R. Rood, M.D., Harold R. Garner, Ph.D., Samuel Rivero-Hinojosa, Ph.D., and Nicholas Kinney, Ph.D.