The relationship between polymorphisms of BDNFOS and BDNF genes and heroin addiction in the Han Chinese population

Background: The number of heroin addicts is increasing in the world. Both environmental and genetic factors both play critical roles in the process of heroin addiction. We aimed to investigate the associations between single nucleotide polymorphisms (SNPs) in LIN7C, BDNFOS and BDNF genes and drug addiction in the Han Chinese population.

Methods: We conducted a case-control study among 692 cases and 700 healthy controls from Xi'an, China. Eight SNPs were selected and genotyped using MassARRAY technology (Sequenom, San Diego, CA, USA). Odds ratios (OR) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression adjusting for age and sex.

Results: Using the chi-squared test, we found that rs7481311 (OR =1.275, 95% CI = 1.087-1.497, p = 0.009) and rs11030096 (OR =1.227, 95% CI = 1.049-1.436, p = 0.011) in the BNDFOS were associated with an increased risk of heroin addiction. By contrast, rs988712 located in BDNFOS showed a decreased risk of heroin addiction (OR =0.734, 95% CI = 0.582-0.925, p = 0.003). By genetic model analysis, we found that the 'T' allele of rs988712 in BDNFOS had a protective role for heroin addiction in the additive model and dominant model (p < 0.05). By contrast, the allele 'T' of rs7481311 in BDNFOS significantly elevated the risk of heroin addiction in the additive model, recessive model and dominant model (p < 0.05). We also found that allele 'C' of rs11030096 was associated with an increased risk of addiction in the dominant model and additive model (p < 0.05). Additionally, we found that rs6265, rs11030104 and rs10767664 in BDNF were associated with a decreased risk of heroin addiction (p < 0.05). However, only rs7481311 in BDNFOS remained significant after Bonferroni correction (p < 0.00625).

Conclusions: These results suggest that polymorphisms of BDNFOS play an important role in heroin addiction susceptibility in the Chinese Han population.