Vitamin D receptor gene polymorphism: association with Crohn's disease susceptibility
- aGastroenterology Unit, University of Oxford, Radcliffe Infirmary, Woodstock Rd, Oxford, OX2 6HE, UK, bTransplant Immunology, Transplant Centre, Churchill Hospital, Oxford, UK
- J D Simmons, Gastroenterology Unit, John Radcliffe Hospital, Oxford, OX3 9DU, UK. Email: jonsimmons{at}doctors.org.uk
- Accepted 8 February 2000
Abstract
BACKGROUND The vitamin D receptor (VDR) gene represents a strong positional candidate susceptibility gene for inflammatory bowel disease (IBD). The VDR gene maps to a region on chromosome 12 that has been shown to be linked to IBD by genome screening techniques. It is the cellular receptor for 1,25(OH)2 vitamin D3 (calcitriol) which has a wide range of different regulatory effects on the immune system. IBD is characterised by activation of the mucosal immune system.
AIM To determine if polymorphisms in the VDR gene are associated with susceptibility to IBD
SUBJECTS European Caucasoids: 158 patients with ulcerative colitis, 245 with Crohn's disease, and 164 cadaveric renal allograft donor controls.
METHOD Single nucleotide polymorphisms (TaqI,ApaI, and FokI) in VDR were typed in patients with Crohn's disease, ulcerative colitis, and controls by polymerase chain reaction with sequence specific primers.
RESULTS There were significantly more homozygotes for the TaqI polymorphism at codon 352 of exon 8 (genotype “tt”) among patients with Crohn's disease (frequency 0.22) than patients with ulcerative colitis (0.12) or controls (0.12) (odds ratio 1.99; 95% confidence interval 1.14–3.47; p=0.017).
CONCLUSION This study provides preliminary evidence for a genetic association between Crohn's disease susceptibility and a gene that lies within one of the candidate regions determined by linkage analysis.
Footnotes
- Abbreviations used in this paper:
- VDR
- vitamin D receptor
- IBD
- inflammatory bowel disease
- PCR-SSP
- polymerase chain reaction with sequence specific primers
- RCLB
- red cell lysis buffer
- IL
- interleukin
