[Wide spectrum of hereditary motor sensory neuropathy (HMSN)]

Hereditary neuropathies are classified into HMSN/Charcot-Marie-Tooth disease (CMT), familial amyloid polyneuropathy (FAP), hereditary motor neuropathies (HMN) and hereditary sensory (and autonomic) neuropathies (HSAN). The clinical features of HMSN are generally characterized as distal dominant motor and sensory involvements. However, we have reported a novel HMSN with proximal dominancy (HMSN-P) originated in Okinawa and Shiga prefectures, Japan. The gene locus is located in the centromere region of chromosome 3. In 2008, a new family with the HMSN-P was reported from Brazilians of Japanese ancestry. This Brazilian family was initially diagnosed as having "a familial ALS". The HMSN-P linked to ch.3 is not limited in Japan, but may be present in the worldwide. The overseas scientific research for the elucidation of the mechanism of HMSN-P supported by JSPS KAKENHI (21406026) is planning. Recently several other types of HMSN-P have been reported; HMSN-P with urinary disturbance and paroxysmal dry cough, a patient with both CMT 1A and mild spinal muscular atrophy and CMT1A with severe paresis of the proximal lower limb muscles. Therefore the clinical concept of HMSN is not limited as the disease with distal dominant motor sensory involvement. HMSN has the wider spectrum from distal to proximal and motor/sensory to autonomic neuropathies.