A nonsense mutation in MME gene associates with autosomal recessive late-onset Charcot-Marie-Tooth disease.

The MME gene encodes for the membrane bound endopeptidase neprilysin (NEP) which is involved in processing of various peptide substrates. The identified mutation causes a complete loss of carboxy-terminal region of the NEP protein which contains the zinc binding site and the catalytic domain and thus considered to be a loss-of-function mutation. The loss of NEP activity is likely associated with impaired myelination and axonal injury which is hallmark of CMT diseases.