CMT is an inherited neurological disease characterized by the gradual degeneration of nerves which starts in the hands and feet and results in progressive numbness, muscle weakness and loss of function. Type 4A has an autosomal recessive inheritance and involves a defect in the GDAP 1 protein gene on chromosome 8. The recessive forms of CMT tend to be more severe than the dominant form and often involve hand and foot problems as well as additional systemic symptoms. See also Charcot-Marie-Tooth disease, Type 4A