HPRT MUTANT FREQUENCIES AND DETECTION OF LARGE DELETIONS BY MULTIPLEX-PCR IN HUMAN-LYMPHOCYTES OF VINYL-CHLORIDE EXPOSED AND NON-EXPOSED POPULATIONS

The frequency of hypoxanthine guanine phosphoribosyltransferase (HPRT) mutations was determined in human T-lymphocytes isolated from periphe ral blood of three populations: (1) 24 employees occupationally expose d to vinyl chloride monomer; (2) 23 healthy non-exposed matched contro l individuals and (3) 41 regular blood donors. In addition, mutant clo nes of all studied groups were examined by multiplex-PCR for visible a bnormalities of the gene (large deletions), Surprisingly, the mutation frequency of all three investigated populations was approximately the same (7-8 x 10(-6)). However, great differences occurred for the spec trum of mutants. Among the mutant clones of the non-exposed healthy in dividuals only 6% (blood donors) and 11% (matched control group) showe d large deletions. The corresponding percentage of large deletions in the occupationally exposed group was, at 21%, much higher.