Chromosomal microarray in unexplained severe early onset epilepsy - A single centre cohort

Background: Severe early onset epilepsy may lead to impaired cognitive and motor development, and consists of a group of specific and overlapping electro-clinical phenotypes which may be the result of an inborn error of metabolism, congenital or acquired structural brain lesion, known chromosomal or mono-genetic disorder. A significant proportion of cases however remain unexplained, representing a major diagnostic and management challenge. Methods: In this study we describe a cohort of children with severe early onset epilepsy and examine the clinical utility of chromosomal microarray (array-comparative genomic hybridisation, CGH) in this group of epilepsies. Results: In 51 children with unexplained severe early onset epilepsy, all of whom had chromosomal array tested, copy number variants were detected in 17.6% and pathogenic variants in 5.9% of infants. Conclusions: Chromosomal microarray is a useful investigation in early onset refractory epilepsy and epileptic encephalopathy. Detailed review of the precise array abnormality and phenotypes associated are important for determining significance. (C) 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.