 polymorphism of cyp2d6 gene encoding for debrisoquine hydroxylase was determined genotypically for 94 controls and 77 lung cancer patients using a polymerase chain reaction - based application . 
 both of the point mutations that give rise to deficient alleles of the cyp2d6 gene are detectable by this method . 
 out of the 94 healthy controls , 3 individuals ( 3.2% ) had poor metabolizer ( pm ) genotypes , whereas no pm genotypes were detected in the lung cancer patient group . 
 we observed no difference in the allelic frequencies for either homozygous extensive metabolizers ( ems ) or heterozygous ems between the lung cancer patients and the healthy controls . 
 however , the absence of the poor metabolizer genotype ( 0/77 ) in the lung cancer patients is compatible with the hypothesis that there is an increased risk of lung cancer for individuals who are extensive metabolizers of debrisoquine . 
 another member of the cytochrome p450 gene superfamily that has attracted interest for its potential role in human pulmonary carcinogenesis is the cyp1a1 gene . in cyp1a1 gene studies , a polymorphic site assessable to mspi gives rise to two different hybridizable fragments in a southern blot analysis ( alleles c1 and c2 , respectively ) . 
 the c2c2 genotype has previously been associated with an increased risk of lung cancer . 
 so far 74 lung cancer patients , 30 patients with lung diseases other than cancer , and 118 healthy controls have been studied for cyp1a1 gene polymorphism . 
 no association between the mspi restriction fragment length polymorphism in the cyp1a1 gene and lung cancer susceptibility has been found.imagesfigure 1 . 
 afigure 1 . 
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