We used probes for DNA polymorphisms on the X chromosome to study genetic linkage in four families with X-linked neuropathy. Despite clinical variability, all four families showed the same linkage pattern. We found evidence in each family of linkage to the marker DXYS1 on the proximal long arm of the X chromosome, as reported by others. We also found linkage to p58—1 (DXS14) on the proximal short arm. We found only loose linkage or nonlinkage to nine other markers located elsewhere on the chromosome. Our analysis places the gene defect for this disorder in the region of DXYS1 and p58—1, near the centromere of the X chromosome.