Infantile convulsions and paroxysmal choreoathetosis in a consanguineous family.
Infantile convulsions and paroxysmal choreoathetosis is a rare autosomal-dominant disorder characterized by variable presentation of benign infantile seizures and paroxysmal dyskinesia. The disease gene was mapped to chromosome 16p12-q12. We report a consanguineous Turkish family with three individuals affected by infantile convulsions and paroxysmal choreoathetosis. Two siblings whose parents were first cousins had benign infantile convulsions and paroxysmal choreoathetosis. Whereas their father presented only paroxysmal choreoathetosis. The siblings displayed an earlier age of onset and increased frequency of the paroxysmal symptoms than their father. We genotyped the pedigree with polymorphic microsatellite markers, spanning the pericentromeric region of chromosome 16. Construction of the haplotypes demonstrated the segregation of the disease with the infantile convulsions and paroxysmal choreoathetosis locus. The disease was inherited as an autosomal-dominant trait with incomplete penetrance. The affected father was heterozygous for the disease haplotype. However, the two affected siblings manifested homozygosity for the disease haplotype. By haplotype analysis, we confirmed the assignment of the locus for infantile convulsions and paroxysmal choreoathetosis to chromosome 16p12-q12 in this family, and our results also demonstrate that homozygotes for infantile convulsions and paroxysmal choreoathetosis may have a more severe form of the disease than heterozygotes.
Demir
Ercan
E
Department of Pediatric Neurology, Hacettepe University, Ankara, Turkey.
Prud'homme
Jean François
JF
Topçu
Meral
M
D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D002819:Chorea / Q000235:genetics* / Q000503:physiopathology; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D003241:Consanguinity; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D008297:Male; D010375:Pedigree; D012640:Seizures / Q000235:genetics* / Q000503:physiopathology