Autosomal dominant distal hereditary motor neuropathy type II: a Korean family without sequence variation in HSPB1 and HSPB8

Distal hereditary motor neuropathy (dHMN) is a heterogeneous group of disorders characterized by weakness and wasting of distal limb muscles without overt sensory abnormalities. Recently, autosomal dominant dHMN has been mapped to chromosome 12q24 and 7q11-q21. We present a family with autosomal dominant adult onset dHMN type II consisting of five affected individuals spanning three generations. They developed mild symmetrical distal lower limb weakness, muscle wasting, and severe foot deformity after the third decade. Genetic analysis showed no support for linkage to chromosome 12q24 and 7q11-q21 in our family. These findings further demonstrate a genetic heterogeneity within dHMN type II.