Familial uveal melanoma: absence of constitutional cytogenic abnormalities in 14 cases.

The study of inherited cancer syndromes offers an opportunity to identify the genetic mechanisms of carcinogenesis. In familial cancers, detection of a constitutional cytogenetic abnormality such as deletion, inversion, or unbalanced translocation has provided clues to the location of the retinoblastoma predisposition gene, RB1 , the neurofibromatosis type I gene, hereditary cutaneous melanoma gene, and others. The genetic basis of inheritance of uveal melanoma is not known, therefore, rare cases of familial uveal melanoma (FUM) offer a unique opportunity for investigation. As a first step for initiating molecular genetic studies, we performed karyotype of constitutional cells (peripheral blood lymphocytes) in 14 probands, derived from the 56 patients with FUM described in this issue of theArchives. 1 We karyotyped constitutional cells by initiating cultures of peripheral blood lymphocytes in enriched RPMI-16 medium containing 10% fetal bovine serum, glutamine, gentamycin, and phytohemagglutinin. After 72 hours the cells were harvested with colcemid and