An Analysis of Transcobalamin II Gene Polymorphisms and Serum Levels of Homocysteine, Folate and Vitamin B12 in Chinese Patients with Crohn's Disease.

Objectives: The study aimed to investigate the association of Crohn's disease (CD) with transcobalamin II (TCN2) polymorphisms and serum homocysteine, folate, and vitamin B-12 levels. Methods: TCN2 (rs1801198, rs9606756) were genotyped by iMLDR in 389 CD patients and 746 controls. Furthermore, 102 CD patients and 153 controls were randomly selected for examination of serum homocysteine, folate, and vitamin B-12 levels by enzymatic cycling assay and chemiluminescence immunoassay, respectively. Results: Mutant allele (G) and genotype (AG + GG) of (rs9606756) were higher in CD patients than in controls (both p < 0.05). So were they in ileocolonic CD patients and stricturing CD patients compared to controls (all p < 0.05). Mutant allele (G) and genotype (CG + GG) of (rs1801198) were more prevalent in stricturing CD patients than in controls (both p < 0.05). Compared to controls, average homocysteine level was enhanced in CD patients (p = 0.003), whereas average folate and vitamin B-12 levels were reduced in CD patients (both p < 0.001). The prevalence of hyperhomocysteinemia, folate deficiency, and vitamin B-12 deficiency was higher in CD patients than in controls (all p < 0.01). Both folate deficiency and vitamin B-12 deficiency were independently related to risk of CD (both p < 0.01). Conclusion: TCN2 (rs1801198, rs9606756) polymorphisms as well as folate deficiency and vitamin B-12 deficiency are correlated with CD. (C) 2017 S. Karger AG, Basel