[Association study of the 5-HTT polymorphism and posttraumatic stress disorder in adolescents]

To study the association between 5-HTTVNTR polymorphism and posttraumatic stress disorder (PTSD) in Chinese Han adolescents after the Wenchuan Earthquake, and investigation of the genetic mechanism of PTSD.

Polymerase chain reaction (PCR) was used to detect the distributive frequency of 5-HTTVNTR polymorphism of 236 PTSD patients (patient group) and 234 normal people (control group), Plink version 1.07 was used to analyze the genotyping results.

The frequency of 5-HTTVNTR allele 12 in PTSD group was significantly higher than control group (93.2% vs. 88.9%, chi2 = 5.42, P = 0.020). The 12/12 genotype in PTSD group and control group was 88.1% and 79.7%; 10/12 genotype was 10.2% and 19.6%; 10/10 genotype was 1.7% and 1.7%. The distributive frequency of all three genotypes (12/12, 10/12, 10/10) showed statistically significant (P = 0.023).

The allele 12 of 5-HTTVNTR may increase the risk of PTSD in Chinese Han adolescents, 12/12 genotype may be the susceptibility gene, and heterozygote 10/12 may act as the protective factor of PTSD.