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Familial neonatal seizures with intellectual disability caused by a microduplication of chromosome 2q24.3
Author(s) -
Heron Sarah E.,
Scheffer Ingrid E.,
Grinton Bronwyn E.,
Eyre Helen,
Oliver Karen L.,
Bain Sharon,
Berkovic Samuel F.,
Mulley John C.
Publication year - 2010
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/j.1528-1167.2010.02558.x
Subject(s) - gene duplication , genetics , scn3a , intellectual disability , biology , gene , medicine , candidate gene , protein subunit , g alpha subunit
Summary A family with dominantly inherited neonatal seizures and intellectual disability was atypical for neonatal and infantile seizure syndromes associated with potassium ( KCNQ2 and KCNQ3 ) and sodium ( SCN2A ) channel mutations. Microsatellite markers linked to KCNQ2 , KCNQ3, and SCN2A were examined to exclude candidate locations, but instead revealed a duplication detected by observation of three alleles for two markers flanking SCN2A . Characterization revealed a 1.57 Mb duplication at 2q24.3 containing eight genes including SCN2A , SCN3A, and the 3′ end of SCN1A . The duplication was partially inverted and inserted within or near SCN1A, probably affecting the expression levels of associated genes, including sodium channels. Rare or unique microchromosomal copy number mutations might underlie familial epilepsies that do not fit within the clinical criteria for the established syndromes.