Late onset distal hereditary motor neuropathy type IIB (dHMN IIB) – case reports

Abstract

Distal hereditary motor neuropathies are a heterogeneous group of rare, genetically determined neuromuscular disorders. Distal hereditary motor neuropathy type IIB is an autosomal dominant disorder, and the onset of symptoms is observed in adulthood. Mutation refers to heat shock protein 27, also known as heat shock protein beta-1. The main symptoms of distal hereditary motor neuropathy type IIB are muscular atrophy and paresis of distal limb muscles. In this article, we present the first Polish case of familial late onset distal hereditary neuropathy type IIB with a T151I mutation (p.Thr151Ile) in one allele of the heat shock protein 27 gene. The first symptoms of the disease in our patients began around the age of 60.

HSPB1 mutation causing distal Hereditary Motor Neuropathy type 2B in a Polish family

“…The family cases were found in Croatia (4 relatives) and in Poland (2 relatives). Four unrelated patients in Japan and one in France were diagnosed with this mutation [5,9,11,12]. The previously described Polish family presented very late onset dHMN2B, with first symptoms occurring in 7th decade, and with pyramidal signs (positive Babiński sign), not very common in this disease [9].…”

“…Usually the first symptoms of dHMN2B occur in 4th decade however, it can range from the 2nd till 6th decade [8]. The progression of the disease is slow [9].…”