Hereditary motor and sensory neuropathy (proximal dominant form, HMSN-P) among Brazilians of Japanese ancestry.

Hereditary motor and sensory neuropathy (proximal dominant form, HMSN-P) has been reported exclusively from Okinawa Prefecture in Japan. We herein report three brothers with HMSN-P who are among Brazilians of Japanese ancestry. They showed the typical clinical manifestations and were compatible with HMSN-P. Okinawa Prefecture has been a site of emigration to other countries, mainly in South America, since 1908. Although this is the first reported familial case of HMSN-P occurring outside Japan, it is estimated that there are 19 or 20 individuals with HMSN-P among these emigrants. Since HMSN-P might be misdiagnosed as familial amyotrophic lateral sclerosis or spinal muscular atrophy, neurologists in countries where individuals of Okinawan extraction reside should be aware of this hereditary neuropathy. HMSN-P should no longer be regarded as an endemic condition limited to Okinawa.