Genome-wide copy number variation in epilepsy: novel susceptibility loci in idiopathic generalized and focal epilepsies.
Epilepsy is one of the most common neurological disorders in humans with a prevalence of 1% and a lifetime incidence of 3%. Several genes have been identified in rare autosomal dominant and severe sporadic forms of epilepsy, but the genetic cause is unknown in the vast majority of cases. Copy number variants (CNVs) are known to play an important role in the genetic etiology of many neurodevelopmental disorders, including intellectual disability (ID), autism, and schizophrenia. Genome-wide studies of copy number variation in epilepsy have not been performed. We have applied whole-genome oligonucleotide array comparative genomic hybridization to a cohort of 517 individuals with various idiopathic, non-lesional epilepsies. We detected one or more rare genic CNVs in 8.9% of affected individuals that are not present in 2,493 controls; five individuals had two rare CNVs. We identified CNVs in genes previously implicated in other neurodevelopmental disorders, including two deletions in AUTS2 and one deletion in CNTNAP2. Therefore, our findings indicate that rare CNVs are likely to contribute to a broad range of generalized and focal epilepsies. In addition, we find that 2.9% of patients carry deletions at 15q11.2, 15q13.3, or 16p13.11, genomic hotspots previously associated with ID, autism, or schizophrenia. In summary, our findings suggest common etiological factors for seemingly diverse diseases such as ID, autism, schizophrenia, and epilepsy.
Mefford
Heather C
HC
Department of Pediatrics, University of Washington, Seattle, Washington, United States of America. hmefford@u.washington.edu
Muhle
Hiltrud
H
Ostertag
Philipp
P
von Spiczak
Sarah
S
Buysse
Karen
K
Baker
Carl
C
Franke
Andre
A
Malafosse
Alain
A
Genton
Pierre
P
Thomas
Pierre
P
Gurnett
Christina A
CA
Schreiber
Stefan
S
Bassuk
Alexander G
AG
Guipponi
Michel
M
Stephani
Ulrich
U
Helbig
Ingo
I
Eichler
Evan E
EE
D004827:Epilepsy / Q000235:genetics*; D018628:Gene Dosage; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D016678:Genome; D006801:Humans