CLINICAL GENETIC-ASPECTS OF CUTANEOUS MAL IGNANT-MELANOMA .2. INTERRELATION AND PATHOGENETIC COMMONALITY WITH DYSPLASTIC NEVUS SYNDROME

Evidence for the role of dysplastic nevi (DN) in the development of cu taneous malignant melanoma (CMM) is presented. Primary multiple foci d f CMM were found considerably more frequently in individuals with DN. The frequency of primary multiple CMM was found to be 3.1% in males wi th DN and 0.9% in males without DN; in females, 6.8 and 0.6%, respecti vely. Genetic correlation analysis was performed to determine the gene tic interrelation between DN and CMM. In general, the genetic correlat ion coefficient was 0.9; i.e., predisposition to DN and CMM is determi ned by common genes for 90%. The frequency and distribution of constit utive fragile sites in chromosomes of peripheral lymphocytes was studi ed by the method of principal components for discrete variables. The s ite 1p22 is responsible for variability of the traits CMM and DN for 9 8.5%. On the one hand, this suggests that one of the supposed genes fo r 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 ar e given with reference to the variants of CMM manifestation and presen ce of DN.