The single-SNP analysis showed that the dominant minor allele of rs2134655 on DRD3 increases alcoholism susceptibility; the dominant minor allele of rs1439047 on NTRK2 delays the alcoholism onset age, but the additive minor allele of rs172677 on GRIN2B and the dominant minor allele of rs63319 on ALDH1A1 advance the alcoholism onset age; and the dominant minor allele of rs1079597 on DRD2 shortens the onset age range.
Also, recent human genetic studies have supported a role of BDNF signaling in addictive behaviors by allele-, genotype-, and haplotype-based association of the TrkB gene, which encodes the cognate receptor for BDNF, with alcohol dependence.
Individually, three SNPs were associated with alcohol dependence and alcohol abuse (AD) (P-value from 0.0019 to 0.0059, significance level was set at P<or=0.01 corrected for multiple testing), whereas a common 18 locus haplotype within the largest LD block of NTRK2, a 119-kb region containing the 5' flanking region and exons 1-15, was marginally overrepresented in control subjects compared to AD individuals (global P=0.057).
Individually, three SNPs were associated with alcohol dependence and alcohol abuse (AD) (P-value from 0.0019 to 0.0059, significance level was set at P<or=0.01 corrected for multiple testing), whereas a common 18 locus haplotype within the largest LD block of NTRK2, a 119-kb region containing the 5' flanking region and exons 1-15, was marginally overrepresented in control subjects compared to AD individuals (global P=0.057).