[Association of serotonin transporter linked polymorphic region 44 bp variable number of tandem repeat polymorphism with Tourette syndrome].

OBJECTIVE

To assess the association between the serotonin transporter linked polymorphic region (5-HTTLPR) 44 bp variable number of tandem repeat (VNTR) polymorphism and Tourette syndrome (TS) in ethnic Han Chinese trios.

METHODS

A total of 252 TS trios (patients and their parents) were recruited. Genetic contribution of the 5-HTTLPR 44 bp VNTR polymorphism was evaluated by genotyping, haplotype relative risk (HRR) analysis and transmission disequilibrium test (TDT) statistics. To enhance the efficiency of the test, haplotype-based HRR (HHRR) was also performed.

RESULTS

The TDT, HRR and HHRR analyses have revealed a significant association of the 5-HTTLPR 44 bp VNTR polymorphism with TS, and provided a strong evidence for an over-transmission of L allele from parents to the affected children (TDT: χ² = 6.680, df= 1, P= 0.012; HRR: χ² = 9.345, P= 0.002, OR= 1.739, 95% CI for 1.218-2.483). For 204 male and 48 female TS trios, TDT and HRR were analyzed separately. The results showed a significant association between 5-HTTLPR and male TS (for males. TDT: χ² = 4.643, df= 1, P= 0.038; for females, TDT: χ² = 2.189, df= 1, P= 0.188).

CONCLUSION

5-HTTLPR may be the susceptibility gene for male TS patients among the Chinese Han population. However, the results need to be replicated in datasets collected from different populations.