Association Between Brain-gut Peptide Polymorphisms and Irritable Bowel Syndrome

Abstract

AIM: Associations between calcitonin gene-related peptide (CGRPα, encoded by CALCA), transient receptor potential vanilloid-1 (TRPV1) and transcription factor 7-like2 (TCF7L2) polymorphisms in IBS were evaluated. METHODS: DNA was obtained from 108 IBS patients [53 diarrheatype (IBS-D), 31 constipation-type (IBS-C), 8 mixed-type (IBS-M), and 16 unsubtyped (IBS-U)] and 61 controls. For all analyses, IBS-M and IBS-U patients were combined into one group (NonDNonC). CALCA, TRPV1 and TCF7L2 polymorphisms were detected by the polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) method. RESULTS: The CALCA, TRPV1 and TCF7L2 genotype frequencies were not significantly different between IBS patients and controls. The genotype distributions were not significantly different between IBS-D, IBS-C and NonDNonC. TRPV1 genotype frequencies were significantly different between patients with <65 years old (y.o.) and ≥65 y.o. Particularly, TRPV1 C/C genotype with ≥65 y.o. in male or disease duration <3 years were trend to be fewer than in female or disease duration ≥3 years. CALCA and TCF7L2 genotype frequencies were not significantly different between patients with <65 y.o. and ≥65 y.o. CONCLUSIONS: TRPV1 polymorphisms in IBS patients would be associated with age. TRPV1 C/C genotype with ≥65 y.o. might be associated with gender and disease duration.