Study of Families With Melanoma

DISEASE CHARACTERISTICS: * Meets 1 of the following criteria: * Newly diagnosed primary invasive melanoma (patient group) * Lentigo maligna malignant melanoma allowed * Rare variants of melanoma allowed, including any of the following: * Acral lentiginous * Subungual * Ear, nose, and throat * Oropharyngeal * Perineal * Vaginal * Vulval * Rectal * Nodal with no known primary * Patients undergoing sentinel node biopsy are eligible * No in situ melanoma, melanocytic intraepidermal neoplasia, or ocular melanoma * Healthy participant meeting either of the following criteria (control group): * Relative of a patient who was diagnosed with melanoma after September 2005 * Healthy volunteer who is age- and sex-matched for patients who were diagnosed with melanoma before October 2005 PATIENT CHARACTERISTICS: * Not specified PRIOR CONCURRENT THERAPY: * Not specified