Genetic polymorphisms of , encoding a small Maf protein, are associated with susceptibility to ulcerative colitis in Japan.

AIM

To investigate whether single nucleotide polymorphisms in maf protein K (), which encodes the , lead to increased susceptibility to ulcerative colitis in the Japanese population.

METHODS

This case control study examined the associations between single nucleotide polymorphisms (rs4268033 G>A, rs3735656 T>C and rs10226620 C>T) and ulcerative colitis susceptibility in 174 patients with ulcerative colitis (UC) cases, and 748 subjects without no lower abdominal symptoms, diarrhea or hematochezia (controls). In addition, as the second controls, we set 360 subjects, who have an irregular bowel movement without abnormal lower endoscopic findings (IBM controls).

RESULTS

The genotype frequency of rs4268033 AA and allelic frequency of the rs4268033A allele were significantly higher in the UC cases than in both controls ( = 0.0005 and < 0.0001, = 0.015 and 0.0027 controls and IBM controls, respectively). Logistic regression analysis after adjustment for age and gender showed that the rs4268033 AA and rs3735656 CC genotypes were significantly associated with susceptibility to UC development (OR = 2.63, 95%CI: 1.61-4.30, = 0.0001 and OR = 1.81; 95%CI: 1.12-2.94, = 0.015, respectively). Similar findings were observed by the comparison with IBM controls. In addition, the rs4268033 AA genotype was significantly associated with all phenotypes of UC except early onset. There was no significant association between rs10226620 and ulcerative colitis.

CONCLUSION

Our results provide the first evidence that genetic polymorphisms are significantly associated with susceptibility to UC development. In particular, rs4268033 is closely associated with an increased risk for the development of UC.