The Grainyhead-Like 2 Gene (GRHL2) Single Nucleotide Polymorphism Is Not Associated with Age-Related Hearing Impairment in Han Chinese

Objectives/Hypothesis: The grainyhead-like 2 gene (GRHL2) was found to be associated with age-related hearing impairment (ARHI) in Europeans. We tested whether the same association exists in the Han Chinese population. Study Design: Individual cohort study. Methods: Among a total of 1,175 Han Chinese volunteers, 310 were classified into the case group (the 26% with poorest hearing), and 308 were placed into the control group (the 26% with best hearing) according to the Z(high) scores converted from the original frequency-specific hearing thresholds. The GRHL2 single nucleotide polymorphism locus (rs10955255: A/G) in intron 1 (coordinate: 102605581) shown in the HapMap was genotyped with correlation to the audiologic phenotypes. Results: The genotype distributions of GRHL2 (AA/AG/GG) were not significantly different between the control and the case groups (P=.349). Compared to genotype AA, the odds ratios of the GRHL2 genotypes AG and GG for ARHI were not significantly different after adjustment for other environmental risk factors by logistic regression analyses; 0.78 +/- 0.139, 95% confidence interval (CI) = 0.55 similar to 1.10, P = .160 for AG; 0.85 +/- 0.283, 95% CI 0.44 similar to 1.63, P = .625 for GG. In each audiogram pattern, AA was most common, but the adjusted odds ratios of the genotypes AG and GG for ARHI still were not significantly different. Conclusions: Our results showed no positive association between GRHL2 polymorphisms and ARHI in Han Chinese individuals. Population differences might be a key factor leading to nonreplication of the association.