HIGH-FREQUENCY OF CYP1A1 MUTATIONS IN A TURKISH POPULATION

The frequency distribution of four cytochrome P4501A1 (CYP1A1) gene mu tations was investigated in 271 Turks from southeast Anatolia by polym erase chain reaction/restriction fragment length polymorphism (PCR/RFL P) assay. Allelic linkage of those mutations was proven by peptide nuc leic acid-mediated PCR clamping. Mutation mi (T6235C) forming an MspI restriction site in the 3'-flanking region occurred with 18.1% frequen cy (95% confidence interval 14.9-21.6%), m2 (A4889G) leading to an Ile /Val exchange in exon 7 had a frequency of 8.9% (6.6-11.6%), and m4 (C 4887A; Thr/Asn-exchange also in exon 7) occurred with 5.7% (3.9-8.0%). T5639C (m3) in the 3'-flanking region was not detected. m2 was exclus ively found linked with mi forming allele CYP1A12B. The frequency of this allele supposedly at-risk for lung cancer was significantly highe r than in Middle European populations, but lower than in the Far East.