Distal hereditary motor neuropathy type Ⅴ :a report of a Chinese family / 中华神经科杂志

ABSTRACT

Objective To report the clinical, pathological and genetic features in a Chinese family with distal hereditary motor ueuropathy type Ⅴ (dHMN-Ⅴ). Methods Four men and 5 women in 4 generations were involved. The onset of disease was from 13 to 40 years old. Six of them showed predominantly weakness of low extremities. Two women had only weakness and atrophy of hand muscle and 1 woman presented additionally pyramidal signs. The proband, a 20 year-old girl, presented asymmetrical atrophy and weakness of both hands since 13 years old. She had weakness of low extremities after 15 years old. Neurogenic changes were observed in the electromyography. Amplitude of compound muscle action potentials were markedly reduced, while the motor nerve conduction velocity were mildly decreased. Sensory nerve conduction velocity and amplitude of action potential were within the normal range. Sural nerve biopsy was performed in the proband. Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) gene were sequenced in the proband and other 4 patients. Results Nerve biopsy showed mild loss of myelinated fibers with a few regeneration cluster of myelinated fibers. DNA analysis revealed a heterozygons 263A→G mutation in exon 3 of BSCL2 gene. Conclusions dHMN-V has been genetically and clinically confirmed in this family. The phynotype is obviously heterogeneous in onset time and clinical symptoms within the same family. The patients present mild pyramidal tract signs and axonal lesions in the sensory nerve.