MAPPING AAC1, AAC2 AND AACP, THE GENES FOR ARYLAMINE N-ACETYLTRANSFERASES, CARCINOGEN METABOLIZING ENZYMES ON HUMAN-CHROMOSOME 8P22, A REGION FREQUENTLY DELETED IN TUMORS

Arylamine N-acetyltransferases (NATs) are encoded at two loci on 8p22, a region subject to deletions in bladder tumours. The two functional genes (AAC1 and AAC2 alias NAT1 and NAT2) without introns in the codin g region, encode enzymes which metabolise carcinogens, including bladd er carcinogens. They are both multi-allelic and certain alleles have b een implicated as susceptibility factors in bladder cancer. There is a third N-acetyltransferase gene, a pseudogene, AACP alias NATP, which we show is also located on chromosome 8 at the p22 region. We have map ped a series of YAC clones (ICI and CEPH) containing the NAT genes and the markers D8S21, an RFLP marker, and D8S261, a microsatellite marke r. We show that D8S21 is a portion of the coding region of AAC2. The o rder of genes in this region, covering some 2 Mb, is TEG D8S261-AAC1-A ACP-AAC2 (D8S21)-CEN. The restriction map also illustrates that there are likely to be other expressed genes in the region through the ident ification of CpG islands.