May 4, 2024

Researchers Identify Cause of Mysterious Cases of Childhood Epilepsy

“Until recently, many health centers did not study resected brain tissue for genetic causes. “However, unlike cancer cells, brain cells mainly do not divide so these cells misbehave by stimulating epileptic seizures.

Seizures are momentary interruptions of the electrical and chemical activity in the brain, leading to physical signs such as convulsions, muscle contractions, loss of awareness, and changes in behavior. In some cases, the cause of epilepsy may stem from spots of harmed or unusual brain tissue understood as “malformations of cortical development” (MCD). Surgical resection or removal of the spot can cure the seizures, and epilepsy surgery to enhance neurological results is now an essential part of the modern medical armamentarium, however what triggers the spots has largely remained a secret.

In a recent paper published in Nature Genetics, scientists at the University of California San Diego School of Medicine and Rady Childrens Institute for Genomic Medicine, working together with a global consortium of more than 20 kidss healthcare facilities worldwide, report a significant breakthrough in comprehending the genetic causes of MCD.
Members of the Focal Cortical Dysplasia Neurogenetics Consortium investigated 283 brain resections from kids across a variety of MCD types, with parental permission, trying to find possible genetic causes. Because most brain tissue in these kids is typical, the researchers concentrated on anomalies present in a little subset of brain cells, a phenomenon called genetic somatic mosaicism.
” This was a decade-long journey, bringing experts together from all over the world, to hire clients for this research study,” stated 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 Childrens Institute for Genomic Medicine. “Until just recently, the majority of healthcare facilities did not study resected brain tissue for hereditary causes. The consortium organized a biobank to store tissue for high-throughput mosaicism analysis.”
An international consortium led by UC San Diego has actually recognized at least some of the hereditary chauffeurs of a mysterious kind of pediatric epilepsy. Credit: UC San Diego Health Sciences
Previous research by Gleeson and coworkers had actually shown that genetic somatic mosaicism in the mTOR signaling path was a contributing aspect, stated co-first author Changuk Chung, PhD, a postdoctoral fellow in the Gleeson lab.
” But most clients remain undiagnosed, which prevents treatment. We evaluated for concealed mutations, noticeable only by significantly broadening the friend size and improving methods so that the results might be meaningful.
The group conducted extensive genomic discovery using state-of-art somatic mosaic algorithms developed by the National Institutes of Health-sponsored Brain Somatic Mosaicism Network, of which UC San Diego is a member.
” We attempted our finest to detect mutations in as low as 1 percent of cells,” stated co-first author Xiaoxu Yang, Ph.D., a postdoctoral scholar in Gleesons lab. “Initially we stopped working. To solve these issues, we needed to develop novel expert system methods to conquer barriers in level of sensitivity and uniqueness.”
The group eventually identified 69 different genes bring somatic brain anomalies, the majority of which have actually never formerly been reported in MCD.
” We can draw parallels with the cancer field due to the fact that these mutations interrupt cellular function and require to be resected,” stated co-first author Chung. “However, unlike cancer cells, brain cells primarily do not divide so these cells misbehave by promoting epileptic seizures. The concern that developed was whether the newly discovered gene anomalies sufficed to trigger MCD disease.”
Gleeson stated the researchers found that the genes converged on calcium signaling, gene expression, and synaptic functions, and noted that when the anomalies were presented into a mouse model, abnormalities comparable to those seen in clients were observed. The study authors suggest the findings might be used to enhance medical diagnosis and develop cures for MCD disease.
” The MCD genes in client brains have demonstrated vital functions throughout cortical development,” stated Gleeson. “These findings could cause brand-new molecular categories for MCD, and eventually to customized therapies for epilepsy.”
Reference: “Comprehensive multi-omic profiling of somatic mutations in malformations of cortical advancement” by Changuk Chung, Xiaoxu Yang, Taejeong Bae, Keng Ioi Vong, Swapnil Mittal, Catharina Donkels, H. Westley Phillips, Zhen Li, Ashley P. L. Marsh, Martin W. Breuss, Laurel L. Ball, Camila Araújo Bernardino Garcia, Renee D. George, Jing Gu, Mingchu Xu, Chelsea Barrows, Kiely N. James, Valentina Stanley, Anna S. Nidhiry, Sami Khoury, Gabrielle Howe, Emily Riley, Xin Xu, Brett Copeland, Yifan Wang, Se Hoon Kim, Hoon-Chul Kang, Andreas Schulze-Bonhage, Carola A. Haas, Horst Urbach, Marco Prinz, David D. Limbrick Jr., Christina A. Gurnett, Matthew D. Smyth, Shifteh Sattar, Mark Nespeca, David D. Gonda, Katsumi Imai, Yukitoshi Takahashi, Hsin-Hung Chen, Jin-Wu Tsai, Valerio Conti, Renzo Guerrini, Orrin Devinsky, Wilson A. Silva Jr., Helio R. Machado, Gary W. Mathern, Alexej Abyzov, Sara Baldassari, Stéphanie Baulac, Focal Cortical Dysplasia Neurogenetics Consortium, Brain Somatic Mosaicism Network and Joseph G. Gleeson, 12 January 2023, Nature Genetics.DOI: 10.1038/ s41588-022-01276-9.
The study was moneyed by the National Institutes of Health, the San Diego Supercomputer Center, and the UC San Diego Institute of Genomic Medicine.

Epilepsy is a neurological condition defined by recurring seizures. Seizures are momentary disruptions of the electrical and chemical activity in the brain, causing physical symptoms such as convulsions, contraction, loss of consciousness, and modifications in behavior. It is estimated to impact over 65 million people worldwide.
International research study groups have discovered a new cause for pediatric seizures: mosaicism, a condition in which cells within the exact same individual have various genetic structures.
Roughly 4% of the population is affected by epilepsy, making it one of the most widespread brain conditions among kids. While modern medicine is efficient in avoiding seizures in the majority of clients, unfortunately, 20% of those with epilepsy do not react to treatment.
Sometimes, the cause of epilepsy may originate from spots of harmed or abnormal brain tissue called “malformations of cortical development” (MCD). These MCDs result in a range of neurodevelopment conditions. Surgical resection or elimination of the spot can cure the seizures, and epilepsy surgery to enhance neurological results is now a key part of the modern medical armamentarium, however what causes the patches has largely stayed a secret.