CYP2D6 genetic polymorphism in South Indian populations.
This study aimed to determine the prevalence of genetic polymorphism in the CYP2D6 gene, which codes for the polymorphically expressed CYP2D6 drug-metabolizing enzyme. The common variants CYP2D6 *2, *3, *4, *5, *10, *14, and *17 were studied in the populations (n=447) of the four South Indian states namely Tamilnadu (TN), Kerala (Ker), Karnataka (Kar) and Andhra Pradesh (AP). Genetic polymorphisms were identified using polymerase chain reaction (PCR) and PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) based methods. Differences in frequencies of CYP2D6 polymorphism between each South Indian state were statistically compared, and also the frequency of South Indian population as a whole in relation to other major populations. The CYP2D6*2 allele was the most frequent variant (34.8%), followed by the *10 allele (10.2%). The *4 and *5 alleles occurred at 7.3% and 1.9% respectively. The *3, *14 and *17 alleles were not detected in the study. The *1/*2, *1/*1 and *2/*2 genotypes were the most common CYP2D6 genotypes, representing 32.7%, 19.4% and 11.8% of the South Indian population. Genotypes that predict poor metabolizer phenotype i.e. *4/*4 and *4/*5 were found at 0.6% in South Indian population. The genetic composition at the CYP2D6 locus in South Indians is distinct from Caucasian, African and even other Asian (Chinese and Japanese) populations.
Naveen
Amrithraj Theophilus
AT
Pharmacogenomics Laboratory, Department of Pharmacology, JIPMER, India.
Adithan
Chandrasekaran
C
Soya
Sisy Sam
SS
Gerard
Nathalie
N
Krishnamoorthy
Rajagopal
R
D000483:Alleles; D001483:Base Sequence; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D017931:DNA Primers; D006801:Humans; D007194:India; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
D017931:DNA Primers; D019389:Cytochrome P-450 CYP2D6