@entity21946 -hydroxylase (P450 2D6) not equal to phenotype was determined in 116 individuals using @entity14031 as the substrate probe. Polymerase chain reaction and restriction fragment length polymorphism analyses were used to detect inactivating mutations in the @entity5320 gene and assign genotype in all 116 individuals. Using a urinary metabolic ratio ( @entity3918 /DT) of > or = 0.3 to define poor metabolizer (PM) phenotypes, 96 subjects were extensive metabolizers (EM) and 20 were PMs. The @entity5320 (B) mutation was the most common mutation, present in 18% of phenotypic EM alleles and 66% of the alleles in PM phenotypes. The @entity5320 (A) mutation (8% of PM alleles) and the @entity5320 gene deletion (2.6% of PM alleles) were found less frequently. Seven different variants of the @entity5320 gene were found. In subjects with two mutant alleles, genotype correctly predicted the PM phenotype in 100% (n = 13). Overall, genotype agreed with phenotype assignments in 109 of 116 (94%) subjects. Seven subjects with a wild-type allele at the @entity5320 (A) and @entity5320 (B) loci were phenotypic PMs, representing the only discrepant results. These discrepancies could be due to the imprecision of phenotype assignment or to as yet unknown mutations in @entity5320 . Although the median urinary metabolic ratio was significantly lower in homozygous EMs compared with heterozygous EMs, there was extensive overlap in metabolic ratios in these two groups, indicating that the @entity3918 /DT metabolic ratio cannot reliably discriminate homozygous EMs from heterozygous EMs.

Concordance of P450 2D6 ( @entity21946 hydroxylase) phenotype and genotype: inability of XXXX metabolic ratio to discriminate reliably heterozygous and homozygous extensive metabolizers.

@entity3918 :: ('MESH:D009223', 'Disease') :: ['DM'] @entity14031 :: ('MESH:D003915', 'Chemical') :: ['dextromethorphan'] @entity21946 :: ('MESH:D003647', 'Chemical') :: ['Debrisoquine'] @entity5320 :: ('1565', 'Gene') :: ['CYP2D6']
@entity14031 :: (MESH:D003915,Chemical) :: ['dextromethorphan']
