Introduction: Phosphorylation of signal transducer and activator of transcription 6 (STAT6) in the colonic epithelium is elevated in ulcerative colitis (UC) patients, and its inhibition prevents IL-13-associated apoptosis and barrier disruption. Recently, the STAT6  rs324015 polymorphism was reported to be related to genetic susceptibility to UC.
Methods: We examined STAT6  rs324015 using the PCR–RFLP method in 268 UC cases and 357 controls. STAT6  expression was determined by quantitative reverse-transcription PCR. The gene–environment interactions were addressed by cross-over analysis.
Results: We found that the STAT6  rs324015 polymorphism enhanced the risk of UC under the homozygous, dominant, and allelic models. Further subgroup analyses indicated that this relationship was more evident in alcohol users, smokers, and those younger than 40 years. Cross-over analysis showed strong interactions of STAT6  rs324015 with smoking/alcohol use. In addition, this polymorphism was associated with the severity, and location of UC. The GG genotype was significantly associated with increased STAT6  gene levels.
Conclusion: In summary, the STAT6  rs324015 polymorphism is related with predisposition to UC in a Chinese Han population.
Keywords: STAT6 , ulcerative colitis, case–control study, rs324015 polymorphism