Absence of linkage with the Duffy blood group in a family with Charcot-Marie-Tooth neuropathy.

We report a large Belgian family with Charcot-Marie-Tooth disease (CMT) or hereditary motor and sensory neuropathy type I (HMSN-I). The pedigree consists of 5 generations with 350 family members comprising 42 patients. The disease is transmitted according to an autosomal dominant inheritance pattern. Several HMSN-I families have been reported to be closely linked to the Duffy blood group marker on chromosome 1. These families were designated HMSN-Ib families, opposed to the HMSN-Ia families which do not show evidence for such a linkage. Therefore we examined our family for the Duffy linkage relationship. We found no evidence for a strong linkage of the disease to the Duffy blood group locus, indicating that this family is of genetic subtype Ia.