Absence of KIF1B mutation in a large Turkish CMT2A family suggests involvement of a second gene.

Abstract

Charcot-Marie-Tooth disease type 2A (CMT2A) was assigned to a 19.3-cM region on chromosome 1p35-36. A missense mutation in the kinesin family member 1B gene (KIF1B) was reported in a single CMT2A family. To report the clinical and genetic data of a Turkish family with CMT2A. Linkage to CMT2 loci was investigated in the family. Haplotype analysis of the CMT2A region was completed using additional single-nucleotide polymorphism and short tandem repeat markers. The KIF1B gene was sequenced on genomic DNA and cDNA in two patients. A recombination event narrowed the CMT2A locus to a 9.3-cM region flanked by D1S160 and D1S434. No mutation in KIF1B was found. The exclusion of KIF1B gene mutations in this family suggests the involvement of another CMT2A gene in the linked region.