Charcot-Marie-Tooth Disease Type 2b1

Charcot-Marie-Tooth disease, type 2B1 (CMT2B1, also referred to as CMT4C1) is an axonal CMT peripheral sensorimotor polyneuropathy.

Epidemiology

It has been described exclusively in families originating from North-Western Africa (northwest Algeria and the east of Morocco).

Clinical description

Onset occurs in the second decade of life. The disease course and severity are variable, even between affected members of the same family. In general, the disease manifests as distal muscle weakness and atrophy that progress gradually to the proximal muscles. Involvement of the upper and lower limbs has been reported. Sensory impairment may also be present but foot deformities are either moderate or absent. Proximal muscle atrophy of the pelvic and scapular girdle may occur later in the disease course.

Etiology

CMT2B1 is caused by a p.R644C missense mutation in the lamin A/C protein (encoded by the LMNA gene, 1q22).

Genetic counseling

CMT2B1 is transmitted in an autosomal recessive manner.