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 2D has an autosomal dominant inheritance and involves a defect in the glycyl RNA synthetase gene on chromosome 7p15. The hands tend to be more severely affected than the feet. See also Charcot-Marie-Tooth disease, Type 2D