CMT2Z is caused by autosomal dominant mutations in the MORC2 gene. CMT2Z is a relatively new type of CMT, having been first reported only recently, in 2016. Researchers believe that CMT2Z might end up being a fairly common type of CMT because there seems to be a high rate of occurrence of the CMT2Z causing MORC2 mutations.
CMT2Z symptoms can start in infancy but can be as late as the CMTer’s late 40s. The first signs are usually generalized weakness, but some can start with signs of proximal (points closest to the center of the body) weakness and sensory loss. For many CMTers who have CMT2Z, some of the first complaints might be severe leg cramping.
CMT2Z tends to be length dependent. This means that the points that are the farthest away from the center of the body tend to be affected first and more severely than points closer to the center of the body. A good example is the sural nerve, which goes down to the feet, and the ulnar nerve, which goes to the hand—the longer the nerve, the more it tends to be affected in CMT2Z.
CMTers who have CMT2Z might experience a progression, over time, which develops into the muscles of the shoulder girdle and neck being affected, and some might become wheelchair-dependent late in the disease course.