To our knowledge, this is the first report of an association between a tobacco-related behavior and the CHRNA10 gene. Three of the four SNPs examined in the CHRNA10 gene were nominally significant at p<0.01, and SNP rs2231532 was the only SNP that reached experiment-wide empirical significance at p=0.048. The α10 nAChR subunit is the most recently discovered subunit and human α10 RNA and protein have been detected in inner-ear tissue, immortalized B-cells, cultured T-cells, and peripheral blood lymphocytes (Lustig et al., 2001). Their location in the inner ear corresponds nicely with a possible involvement in mediating a “dizziness” phenotype. Although the α10 subunit has not been shown to produce functional receptors alone, co-injection with α9 leads to robust acetylcholine-evoked currents, suggesting these receptors are likely to be targets for nicotine as well (Sgard et al., 2002). This potential biological relevance of the CHRNA10 gene suggests future studies examining the “dizziness” endophenotype will be of value.
