CDKN2A germ-line mutations in individuals with multiple cutaneous melanomas

Area of Science:

• Genetics
• Oncology
• Dermatology

Background:

• Hereditary cutaneous melanoma is linked to germ-line CDKN2A mutations.
• A specific founder mutation (113insR) exists in Sweden.
• Identifying individuals with multiple melanomas is crucial for understanding genetic predispositions.

Purpose of the Study:

• To screen individuals with multiple primary cutaneous melanomas for germ-line CDKN2A mutations.
• To characterize the identified CDKN2A alterations and their functional impact.
• To assess the clinical significance of CDKN2A mutations in melanoma predisposition.

Main Methods:

• Screening of 80 individuals with at least two primary melanomas for germ-line CDKN2A mutations.
• Cancer registry search for patient identification.
• In vitro binding assays to assess mutant p16 protein function.
• Comparison of clinical features between mutation carriers and non-carriers.

Main Results:

• Nine patients (11.25%) had detectable CDKN2A alterations.
• Six individuals carried the 113insR founder mutation; one had a 24-bp deletion affecting p16 binding to CDKs.
• Two patients without family history had distinct CDKN2A alterations.
• CDKN2A mutation carriers presented with earlier age at diagnosis, higher number of melanomas, and more frequent family history.

Conclusions:

• Mutation screening in individuals with multiple primary melanomas is effective for identifying new hereditary melanoma kindreds.
• Germ-line CDKN2A mutations are associated with a significantly increased risk and earlier onset of melanoma.
• Understanding these mutations can improve genetic counseling and risk assessment for melanoma.