Concordance between the deduced acetylation status generated by high-speed: real-time PCR based NAT2 genotyping of seven single nucleotide polymorphisms and human NAT2 phenotypes determined by a caffeine assay.
BACKGROUND
The utility of typing single nucleotide polymorphisms (SNPs) for the determination of the N-acetyltransferase 2 (NAT2) acetylation status is a matter of debate.


OBJECTIVE
Evaluation of the concordance between deduced genotype results of seven human NAT2 SNPs generated by Real-time PCR analysis and human NAT2 phenotypes.


METHODS
NAT2 phenotypes of 38 Caucasian workers were determined using a suitable caffeine test method. Genomic DNA aliquots were used for the determination of seven human NAT2-specific SNPs (G191A, C282T, T341C, C481T, G590A, A803G, G857A).


CONCLUSIONS
Phenotypic results based on the molar ratio of 5-acetylamino-6-formylamino-3-methyluracil (AFMU)/(AFMU+1-methlyuric acid (1U)+1-methylxanthine (1X)) calculated from excreted caffeine metabolite levels in urine samples with 0.3 as a cut-off point between slow (<0.3) and rapid acetylators (>or=0.3). Twenty-seven samples belonged to the slow (mean 0.13; range: 0.03-0.25), 11 to the rapid (mean: 0.41; range: 0.34-0.48) acetylators. LightCycler analyses revealed 11 different NAT2 variant combinations, whereby *5B/*5B and *5B/*6A or *5A/*6C (each 21%), were the most frequent. The deduced acetylation status of the seven NAT2 SNPs matched perfectly with the 38 results determined by phenotyping. This study showed a 100% concordance between NAT2 phenotypes and the deduced NAT2 genotypes and the suitability of the high-speed NAT2-specific LightCycler analysis in a Caucasian population.
Rihs
Hans-Peter
HP
Berufsgenossenschaftliches Forschungsinstitut für Arbeitsmedizin (BGFA), Ruhr University of Bochum, Buerkle-de-la-Camp-Platz 1, 44789 Bochum, Germany. rihs@bgfa.de
John
Andrea
A
Scherenberg
Michael
M
Seidel
Albrecht
A
Brüning
Thomas
T
D000107:Acetylation; D000328:Adult; D001191:Arylamine N-Acetyltransferase / Q000235:genetics* / Q000378:metabolism; D001711:Biotransformation / Q000235:genetics; D002110:Caffeine / Q000378:metabolism* / Q000493:pharmacokinetics; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D014498:Uracil / Q000031:analogs & derivatives / Q000652:urine; D014527:Uric Acid / Q000031:analogs & derivatives / Q000652:urine; D044465:White People; D014970:Xanthines / Q000652:urine
D014970:Xanthines; D014527:Uric Acid; C030530:1-methyluric acid; D002110:Caffeine; D014498:Uracil; C053085:1-methylxanthine; C036692:5-acetylamino-6-formylamino-3-methyluracil; D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human; C054188:5-acetylamino-6-amino-3-methyluracil; C053084:1,7-dimethyluric acid