Bitter taste receptor gene polymorphisms are an important factor in the development of nicotine dependence in African Americans.
BACKGROUND
Bitter sensitivity varies among individuals and ethnic groups partly due to polymorphisms in taste receptor genes (TAS2Rs). Although previous psychophysical studies suggest that taste status plays a role in nicotine dependence (ND), genetic evidence is lacking.


OBJECTIVE
To determine whether single nucleotide polymorphisms (SNPs) in TAS2R16 and TAS2R38 are associated with ND and if the effects differ by sex and ethnicity.


METHODS
2037 individuals from 602 nuclear families of African American (AA) or European American (EA) origin were recruited from the US mid-south states during 1999-2004.


METHODS
ND was assessed by three measures: indexed Smoking Quantity (SQ), Heaviness of Smoking Index (HSI), and the Fagerström Test for Nicotine Dependence (FTND). Peripheral blood samples were obtained for DNA extraction and genotyping.


RESULTS
The TAS2R38 taster haplotype PAV was inversely associated (p = 0.0165), and the non-taster haplotype AVI was positively associated (p = 0.0120), with SQ in AA smokers. The non-taster haplotype was positively associated with all ND measures in AA female smokers (p = 0.01 approximately 0.003). No significant associations were observed in the EA sample.


CONCLUSIONS
TAS2R38 polymorphisms are an important factor in determining ND in AAs. Heightened oral sensitivity confers protection against ND. Conversely, decreased sensitivity represents a risk factor for ND, especially in AA females. Together, our findings suggest that taster status plays a role in governing the development of ND and may represent a way to identify individuals at risk for developing ND, particularly in AA smokers.
Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville VA 22911, USA.
J E
JE
Mangold
T J
TJ
Payne
J Z
JZ
Ma
G
G
Chen
M D
MD
Li
D000328:Adult; D001741:Black or African American / Q000235:genetics*; D005260:Female; D006239:Haplotypes; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D012737:Sex Factors; D014029:Tobacco Use Disorder / Q000208:ethnology* / Q000235:genetics*; D000098706:Taste Receptors, Type 2
D043562:Receptors, G-Protein-Coupled; D000098706:Taste Receptors, Type 2