OBJECTIVETo explore the molecular genetic mechanism of complicating depression in asthma by detecting two gene polymorphisms of 5-hydroxytryptamine transporter (5-HTTLPR/Stin2) gene.

METHODSOne hundred fifty-six adults with asthma were collected, and divided into group of asthma with depression (HAMD score > or = 8) and group of asthma without depression or single asthma (HAMD score <8) according to the score of Hamilton depression scale (HAMD). A total of 508 adults with depression alone and 433 healthy individuals were enrolled as controls. The target gene fragments containing the polymorphic regions of 5-HTTLPR and Stin2 were amplified by polymerase chain reaction (PCR). The amplified fragments were then analyzed using agarose gel electrophoresis (AGE) and motored molecular imaging system.

RESULTSThe frequencies of genotype and allele distribution of the Stin2 polymorphism showed that males with genotype Stin2.12/Stin2.10 and allele Stin2.10 had higher risk for asthma than the others (Stin2.12/Stin2.10: OR = 2.291, 95% CI: 1.195 and 4.390; Stin2.10: OR = 1.942, 95% CI: 1.069-3.527). No significant difference was found in the frequencies of genotype and allele distribution of the 5-HTTLPR locus between the asthma and healthy control groups and the two stratified by gender.

CONCLUSIONThe Stin2 polymorphism may play a role in the onset of male asthma. There might be association between the genetic pathogenesis of asthma and depression.