OBJECTIVETo 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.

METHODSA 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.

RESULTSThe 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).

CONCLUSION5-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.

Adolescent ; Asian Continental Ancestry Group ; genetics ; Child ; Child, Preschool ; China ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Linkage Disequilibrium ; Male ; Minisatellite Repeats ; genetics ; Polymorphism, Genetic ; Serotonin Plasma Membrane Transport Proteins ; genetics ; Sex Factors ; Tourette Syndrome ; genetics ; Young Adult