Can Be Homozygous or Can Be Compound Heterozygous
CMT2B3 is caused by autosomal recessive mutations in the GDAP1 gene. Other mutations in this gene are associated with causing several other types of CMT. CMT2B3 is also known as Autosomal Recessive CMT2C, or AR-CMT2C for short.
CMT2B3 symptoms usually start to occur when the CMTer is a toddler. A CMTer who has CMT2B3 will usually experience a particularly severe disease course that includes rapid progression to severe distal (farthest points away from the center of the body) and proximal (closest to the center of the body) weakness and sensory loss.
CMTers who have CMT2B3 might not have the ability to ever walk and might also experience vocal cord paresis (muscle weakness causing slight or partial paralysis).
In nerve conduction studies, CMTers who have CMT2B3 often will have absent sensory responses and varied slowing of conduction velocities that are consistent with an axonal CMT (>37 meters/sec).