Copy number variation in genetic epilepsy with febrile seizures plus.

Aim: Genetic epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome in which affected individuals may have a variety of epilepsy phenotypes, the most common being febrile seizures (FS) and febrile seizures plus (FS+). We investigated the possible contribution of copy number variation to GEFS+.
Method: We searched our epilepsy research database for patients in GEFS + families who underwent chromosomal microarray analysis. We reviewed the clinical features and results of genetic testing in these families.
Results: Of twelve families with available microarray data, four had at least one copy number variant (CNV) identified. In Family 1, the proband had a maternally-inherited 15q11.2 deletion. In Family 5, four different CNVs were identified, variably present in the affected individuals; this included a 19p13.3 deletion affecting CACNA1A. Finally, in both Families 9 and 10, the proband had Dravet syndrome with pathogenic SCN1A variant, as well as a CNV (10q11.22 duplication in Family 9 and 22q11.2 deletion in Family 10).
Interpretation: The significance of these specific variants is difficult to precisely determine; however, there appeared to be an overrepresentation of CNVs in this small cohort. These findings suggest chromosomal microarray analysis could have clinical utility as part of the workup in GEFS + families.
Competing Interests: Declaration of competing interest Dr. Myers receives/received research support related to this project from the Research Institute of the McGill University Health Centre and Citizens United for Research in Epilepsy.
(Copyright © 2020 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)