The Relationship between Single Nucleotide Polymorphisms of the Carbonic Anhydrase 6 Gene andPhenylthiocarbamide Taste Sensitivity, Taste Disorder / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) taste sensitivity varies among individuals. Recently, it is reported that PROP taste responsiveness is associated with carbonic anhydrase 6 (CA6) gene polymorphism. The CA6 gene, a zinc metalloprotein in human saliva, is affected in taste function and might be correlated with gustatory diversity. The aim of this study was to examine whether PTC taste sensitivity and taste disorder is associated with the CA6 gene polymorphism rs2274327 (C/T), rs2274328 (A/C), and rs2274333 (A/G). SUBJECTS AND METHOD: A total of 217 healthy normal subjects were recruited as controls, and 50 taste disorder patients were recruited as experimental group. The polymorphisms of CA6 gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. All statistical analyses were calculated using the statistical package for the social science software. Haplotypes were estimated by Haploveiw and the PHASE programs. RESULTS: The CA6 gene polymorphisms showed association with taste disorder but not with PTC sensitivity (taster/nontaster). The number of control subjects carrying AA genotype of single nucleotide polymorphism rs2274328 (A/C) in the CA6 gene was higher than the number of the subjects with taste disorder (p=0.048). However, there was no association between controls and taste disorder subjects in the haplotype analysis. CONCLUSION: These data suggest that the CA6 gene polymorphism rs2274328 could affect taste function impairment in patients with taste disorder. This observation requires a further functional study of gustin protein to clarify the association of the CA6 gene polymorphisms with the taste disorder and sensitivity.

Relationship between Taste Genotype and Smoking and Alcohol Intake / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Genetic variations of bitter taste receptors (TAS2R) have shown different responses to bitter taste compounds and the frequencies of these variations were different within and between populations. Recently, single nucleotide polymorphisms (SNPs) in the TAS2R38 and TAS2R16 genes demonstrated a significant association with smoking and alcohol consumption in several studies. The aim of this study was to determine the relationship between bitter taste gene polymorphism and cigarette smoking and alcohol intake in Korean. SUBJECTS AND METHOD: One hundred seventy four healthy normal volunteers were asked to fill in a questionnaire regarding demographic information, smoking history, frequency of alcohol intake. Peripheral blood samples were obtained for DNA extraction and genotyping. Single nucleotide polymorphisms were identified on the TAS2R38 and TAS2R16 genes. RESULTS: Haplotype analyses of the three SNPs inside the TAS2R38 gene allowed identifying of only two haplotypes that were associated with the non-taster phenotype (AVI homozygous) and the taster phenotype (PAV homozygous and PAV/AVI heterozygous). Common SNP within TAS2R16, which results in aminoacid change in the protein (K172N), is not demonstrated in this study. Smokers and frequent drinkers were more prevalent among non-tasters than tasters in male. CONCLUSION: Functional variants in TAS2R38 correlated with cigarette smoking in the Korean male. Our findings suggest that taster status plays a role in governing the development of nicotine dependence.