Familial cutaneous malignant melanoma: autosomal dominant trait possibly linked to the Rh locus.

Segregation and linkage analyses were undertaken in families with multiple cases of cutaneous malignant melanoma (CMM) and a recently-described melanoma precursor, the dysplastic nevus syndrome (DNS). Clinical and laboratory data, including 23 genetic markers, were collected on 401 members of 14 high-risk kindreds. Pedigree analysis was compatible with an autosomal dominant mode of inheritance for the familial CMM trait. Although a similar model probably applies to the DNS trait as well, segregation analysis could not confirm the presence of a major locus. However, linkage analysis suggested that an autosomal dominant model was appropriate for the DNS, and that a DNS/CMM susceptibility gene may be located on the short arm of chromosome 1, within 30 map units of the Rh locus [maximum logarithm of odds (lod) score = 2.00].