Mutations in the myelin protein zero gene associated with Charcot-Marie-Tooth disease type 1B

Charcot‐Marie‐Tooth type 1 (CMT1) disease is an autosomal dominant neuropathy of the peripheral nerve. The majority of CMT 1 cases are due to a duplication of an 1.5‐Mb DNA fragment on chromosome 17pl1.2 (CMT la). Micromutations were found in the gene for peripheral myelin protein 22 (PMp22) located in the duplicated region of CMT la, and in the peripheral myelin protein zero (PO) located on chromosome lq21‐23 (CMT Ib). We have characterized two new mutations in the PO gene in two french families presenting CMT disease. Both mutations occur in the extracellular domain of the PO protein. One mutation is a de novo mutation and is from paternal origin. © 1995 Wiley‐Liss, Inc.