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Malignant Melanoma - CDKN2A (p16)

Clinical Features

Malignant melanomas represent 2 to 5% of all malignant tumors. 10% of the cases show a positive family history and are thus considered to be genetically determined. The possibility of a familial predisposition has to be suspected when two first-grade relatives are affected or when more than two malignant melanomas have been diagnosed in one family member. In about 10 to 20% of such cases, genetic alterations of the p16 gene can be detected. The identification of the underlying genetic defect helps to identify at-risk family members with the need for intensive screening programs and clinical surveillance. Furthermore, minimal sun exposition has to be recommended.

Genetic Information

The p16 gene (CDKN2A; cyclin dependent kinase inhibitor 2A) is located on chromosome 9 (9p21); genetic alterations are associated with an increased risk for malignant melanoma and a slightly increased risk to develop pancreatic carcinoma.

Prevalence

Approximately 10% of all malignant melanomas show a familial inheritance; in 10-20% of those cases genetic alterations in the p16 gene are found.

Diagnostic