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

The heat-shock protein beta-1 (HSPB1) is one of small heat-shock proteins that play an important role in cell functioning by promoting correct folding of other proteins. The HSPB1 mutations are known to cause distal Hereditary Motor Neuropathy type 2B (dHMN2B) and Charcot-Marie-Tooth disease type 2F (CMT2F). More than 30 different mutations in the HSPB1 have been found in patients with CMT2F and dHMN2B. There are cases of the Thr151Ile HSPB1 mutation described in 4 countries: Croatia, Japan, France and Poland. In this paper we present a Polish family with p.Thr151Ile mutation causing distal hereditary motor neuropathy. A 48-year-old male patient presented progressive bilateral lower limb weakness and gait difficulty of typical onset. The presentation of the disease in his daughter, who carries the same mutation is yet uncertain. She has currently no clinical symptoms of the disease but registered mild muscle damage in EMG with correct conduction parameter in ENG.