Background: The Italian Society of Human Genetics'(SIGU) recommendations on genetic counseling and testing for hereditary melanoma state that clinical genetic testing can be offered to Italian melanoma families with at least two affected members. Objective: In the framework of a cooperative study, we sought to establish the frequency of cyclin-dependent kinase inhibitor 2,4 mutations in melanoma families that underwent clinical genetic Counseling and testing in accordance with die SIGU recommendations at 9 centers in different Italian regions. Methods: inhibitor 2A testing was conducted by direct sequencing and multiplex ligation-dependent probe amplification analysis in melanoma families with at least two affected members. Results: A total of 33% (68/204) of the families harbored cyclin-dependent kinase inhibitor 2A Mutations. In the 145 families with two affected members the mutation frequency was 25%. Three novel mutations, L94P, A86T, and c.407dupG, were identified among the cases and not in 200 controls. Limitations: We were unable to perform separate analyses for individual centers, as in some cases the number of families was too small. Conclusions: The availability of clinical genetic testing for melanoma to families with just two affected members in the same branch is justified in Italy in terms of the likelihood of identifying a mutation. (J Am Acad Dermatol 20001:775-82.)
