04 Dec 2023
30 Nov 2023
The distal hereditary motor neuropathies (dHMN) also known as spinal form of Charcot–Marie–Tooth disease (CMT) is a group of clinically and genetically heterogeneous inherited neuromuscular disorders characterized by the degeneration of alpha motor neurons in the peripheral nervous system leading to slowly progressive distal symmetric limb muscle weakness and atrophy. More than thirty genes have been reported today to be associated with the dHMN disease. After clinical and neurological investigations of one dHMN Moroccan patient of 5 other affected family members by a neurologist, we performed a whole exome sequencing (WES) followed by a Sanger confirmation of the available members of the family. The proband had the first muscular signs at the age of 34 years starting with a progressive muscle weakness and atrophy in the two lower limbs leading to an axonal bilateral and symmetrical motor neuropathy in lower limbs with absence of overt sensory abnormalities was noticed. WES analysis revealed a HSPB1 pathogenic heterozygous variant c.452C>T, p.(Thr151Ile). This study identifies, in the first Moroccan family, a heterozygous variant in HSPB1 gene as a cause of the dominant form of distal hereditary motor neuropathy (dHMN).