Genome-wide sequencing in children with epilepsy and developmental disorders

Abstract

The progress of genetic diagnostic methods and a significant improvement in the quality of next-generation sequencing (NGS) have led to a revolution in the study of the genetics of epilepsy. Genome-wide sequencing (PSG) is the «gold standard» in genetic research in epilepsy.Material and methods. Genome-wide sequencing was performed in 168 probands aged from 1 month to 18 years with a suspected diagnosis of genetic epilepsy. PSG was prescribed to patients who, alongside with epilepsy, had delayed intellectual/speech development and/or motor disorders and behavioral disorders.Results. According to the results of PSG, genetic variants related to the phenotype of the disease were detected in 137 out of 168 (81.5%) children, variations in the number of DNA copies were noted in 14 out of 168 (8.3%) patients. Variants with unclear clinical significance were described in 35 of 137 (25.54%). In the remaining 102 out of 137 (74.45%) patients, the identified causative genetic variants were described as probably pathogenic and pathogenic. Monogenic developmental and epileptic encephalopathies (DEE) were detected in 37/137 or 27% of all patients, while the spectrum of these genetic encephalopathies was extremely wide (from DEE type 1 to DEE type 97). In 52/137 (37.9%) children, the presence of a specific genetic syndrome outside the framework of the DEE, classified in OMIM, was confirmed.Conclusion. The results confirm the high informative value of genome-wide sequencing in a group of children with a combination of epilepsy, intellectual, speech, motor and behavioral disorders. In most cases, the results allow either to prescribe a genotype-oriented symptomatic (less often pathogenetic) treatment, or rationally justify the tactics of further observation and examination, as well as to increase the effectiveness of medical and genetic counseling. The authors express their sincere gratitude to the Charity foundation for medical and social genetic aid projects «Life Genome” for assistance in conducting genome-wide sequencing of most of the described patients.