April 3, 2023

Researchers Identify Cause of Mysterious Cases of Childhood Epilepsy

Article published by  SciTechDaily

International research teams have uncovered a new cause for pediatric seizures: mosaicism, a condition in which cells within the same individual have different genetic compositions.

Approximately 4% of the population is affected by epilepsy, making it one of the most prevalent brain disorders among children. While modern medicine is effective in preventing seizures in the majority of patients, unfortunately, 20% of those with epilepsy do not respond to treatment.

In some cases, the cause of epilepsy may stem from patches of damaged or abnormal brain tissue known as “malformations of cortical development” (MCD). These MCDs result in a variety of neurodevelopment disorders. Surgical resection or removal of the patch can cure the seizures, and epilepsy surgery to improve neurological outcomes is now a key part of the modern medical armamentarium, but what causes the patches has largely remained a mystery.

In a recent paper published in Nature Genetics, researchers at the University of California San Diego School of Medicine and Rady Children’s Institute for Genomic Medicine, collaborating with an international consortium of more than 20 children’s hospitals worldwide, report a significant breakthrough in understanding the genetic causes of MCD.

Members of the Focal Cortical Dysplasia Neurogenetics Consortium investigated 283 brain resections from children across a range of MCD types, with parental consent, looking for potential genetic causes. Because most brain tissue in these children is normal, the scientists focused on mutations present in a small subset of brain cells, a phenomenon termed genetic somatic mosaicism.

“This was a decade-long journey, bringing specialists together from around the world, to recruit patients for this study,” said senior study author Joseph Gleeson, MD, Rady Professor of Neuroscience at UC San Diego School of Medicine and director of neuroscience research at the Rady Children’s Institute for Genomic Medicine. “Until recently, most hospitals did not study resected brain tissue for genetic causes. The consortium organized a biobank to store tissue for high-throughput mosaicism analysis.”