DELETION MAPPING IDENTIFIES LOSS OF HETEROZYGOSITY AT 5P15.1-15.2, 5Q11 AND 5Q34-35 IN HUMAN MALE GERM-CELL TUMORS

Cytogenetic and loss of heterozygosity (LOH) studies of chromosome 5 i n male germ cell tumors (GCTs) previously reported suggested the prese nce of one or more tumor suppressor genes (TSGs) on this chromosome wh ich may play a role in the development of these tumors, In an attempt to further characterize allelic deletions on chromosome 5, we performe d a detailed deletion mapping utilizing 66 normal-tumor DNAs from male GCTs assaying 24 polymorphic markers mapped to both the short and lon g arms, Thirty-seven (56%) tumors exhibited LOH at one or more loci, L oss of one allele at all informative loci was found in 15 of 37 (40.5% ) cases suggesting monosomy of chromosome 5, The pattern of LOH in the remaining 22 (59.5%) tumors revealed regional losses identifying thre e common sites of deletions at 5p15.1-15.2, 5q11, and 5q34-35, respect ively, The distribution of allelic deletions was found to be similar i n all histologic subtypes with predominance of monosomy in teratomas, Thus, the present study revealed 2 types of chromosome 5 abnormalities in male GCTs, genetic monosomy and regional deletion, the latter iden tifying three novel sites of candidate TSGs, These data suggest that l oss of genetic information on chromosome 5 plays an important role in male GCT development.