CHROMOSOMAL GAINS AND LOSSES IN UVEAL MELANOMAS DETECTED BY COMPARATIVE GENOMIC HYBRIDIZATION

Eleven uveal melanomas were analyzed using comparative genomic hybridi zation (CGH). The most abundant genetic changes were loss of chromosom e 3, overrepresentation of 6p, loss of 6q, and multiplication of 8q. T he smallest overrepresented regions on 6p and 8q were 6pter-->p21 and 8q24-->qter, respectively. Several additional gains and losses of chro mosome segments were rpeatedly observed, the most frequent one being l oss of 9p (three cases). Monosomy 3 appeared to be a marker for ciliar y body involvement. CGH data were compared with the results of chromos ome banding. Some alterations, e.g., gains of 6p and losses of 69, wer e observed with higher frequencies after CGH, while others, e.g., 9p d eletions, were detected only by CGH. The data suggest some similaritie s of cytogenetic alterations between cutaneous and uveal melanoma. In particular, the 9p deletions are of interest due to recent reports abo ut the location of a putative tumor-suppressor gene for cutaneous mali gnant melanoma in this region.