Open AccessIdentification of genetic characteristics in pediatric epilepsy with focal cortical dysplasia type 2 using deep whole‐exome sequencing
Author(s) -
Xu Yan,
Zhao Rui,
Wang Min,
Wang Xinhua,
Wang Yi,
Li Hao,
Ma Yangyang,
Wu Bingbing,
Zhou Yuanfeng
Publication year - 2022
Publication title -
molecular genetics and genomic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 29
ISSN - 2324-9269
DOI - 10.1002/mgg3.2086
Subject(s) - cortical dysplasia , exome sequencing , somatic cell , germline , biology , exome , deep sequencing , genetics , epilepsy , germline mutation , gene , phenotype , genome , mutation , neuroscience
Background Focal cortical dysplasia type 2 (FCD2) is a malformation of cortical development that constitutes a common cause of pediatric focal epilepsy. Germline or somatic variants in the mammalian target of rapamycin (mTOR) signaling pathway genes are the pathogenesis of FCD2. Objective In this study, whole‐exome deep sequencing was performed on dysplastic cortex from focal epilepsy in children to explore genetic characteristics in FCD2. Methods Resected core lesions of FCD2 were confirmed by pathology, and peripheral blood was collected from 11 patients. Deep whole‐exome sequencing (>500X) was performed on derived genomic DNA, germline, or somatic variants in brain‐specific genes were analyzed and identified. Results In 11 patients, a heterozygous likely pathogenic germline variant of DEPDC5 was identified in one case, while somatic variants were found in four brain samples. The frequencies of the somatic variant allele were 2.52%–5.12%. Somatic variants in AKT3 , TSC2, and MTOR (mTOR signaling pathway genes) were found in three samples. Besides, one somatic variant was detected in MED12 which has not been reported to associate with FCD2. Conclusion Our study expanded the variant spectrum in the mTOR‐GATOR pathway, and also detected a somatic variant in MED12 which was potentially associated with FCD 2.