CMT2B1 is caused by autosomal recessive mutations in the LMNA gene. CMT2B1 is also known as Autosomal Recessive CMT2A, or AR-CMT2A for short.
CMT2B1 symptoms usually start to occur between the CMTers early teens and mid-20s. Once symptoms start to show, progression can happen exceedingly rapid. Within sometimes a matter of months of the first signs of CMT, the CMTer’s arms and hands can become very weak. Pelvic girdle weakness can become significant by about 4 years after the first symptoms start. The pelvic girdle is the structure that connects the upper body to the legs and lower body. Some, however, do not experience the typical rapid progression or proximal (closest to the center of the body) limb weakness.
CMT2B1 is primarily seen only in the countries of northern Africa. The countries of northern Africa tend to have a high occurrence rate of the CMT2B1 causing autosomal recessive LMNA “Arg298Cys” mutation (Tazir et al., (2004)).