Molecular and immunohistochemical analyses of uveal melanoma patient cohort.

Uveal melanoma is a rare form of melanoma and the most frequent primary eye malignancy in adults. The major molecular alterations underlying uveal melanoma pathogenesis affect mainly the GNAQ, GNA11, SF3B1, and BAP1 genes. In this study, we somatically genotyped 31 Brazilian uveal melanomas for BRAF, GNA11, GNAQ, SF3B1, and BAP1 gene mutations and assessed BRCA2 and p53 protein expression. GNAQ and GNA11 mutations were detected in 60%, and SF3B1 mutation rate was 30%. p53 Immunostaining was markedly positive in 5/31, and 3/31 samples showed negative BRCA2 expression. This study supports the importance of these key genes in uveal melanoma tumorigenesis; p53 and BRCA pathways seem to play a role in a subset of patients, possibly heralding unfavorable prognosis.