[Clinico-genetic aspects of cutaneous melanoma. II. Interconnection and pathogenetic commonality with dysplastic nevus syndrome].

Evidence for the role of dysplastic nevi (DN) in the development of cutaneous malignant melanoma (CMM) is presented. Primary multiple foci of CMM were found considerably more frequently in individuals with DN. The frequency of primary multiple CMM was found to be 3.1% in males with DN and 0.9% in males without DN; in females, 6.8 and 0.6%, respectively. Genetic correlation analysis was performed to determine the genetic interrelation between DN and CMM. In general, the genetic correlation coefficient was 0.9; i.e., predisposition to DN and CMM is determined by common genes for 90%. The frequency and distribution of constitutive fragile sites in chromosomes of peripheral lymphocytes was studied by the method of principal components for discrete variables. The site 1p22 is responsible for variability of the traits CMM and DN for 98.5%. On the one hand, this suggests that one of the supposed genes for CMM can be located at 1p22; on the other hand, CMM and DN are likely to have a common genetic determination or to be very tightly linked. Estimates of risk for the development of CMM in patients' relatives are given with reference to the variants of CMM manifestation and presence of DN.