Objective: To study the association between the polymorphisms of vitamin D receptor (VDR) gene and autoimmune liver diseases and (AIH) and primary biliary cirrhosis (PBC) in Chinese.
Methods: PCR-RELP was used to investigate the polymorphisms in exon 2, and exon 7 to exon 9 of VDR among 49 AIH patients, 58 PBC patients, and 160 healthy controls, all Chinese. VDR polymorphisms were assessed by FokI, BsmI, ApaI, and TaqI endonucleases restriction fragment length polymorphism analysis after specific polymerase chain reaction (PCR) amplification.
Results: The distribution of VDR gene polymorphism in Chinese was similar to those in Koreans and Japanese, and different from those in the Germans and Spaniards. The percentage of ff phenotype carriers was significantly higher in the AIH patients than in the healthy controls (34.7% vs. 48.1%, chi(2) = 5.47, P = 0.019) and the percentage of Ff phenotype carriers was lower in the AIH patients than in the healthy controls (34.7% vs. 48.1%, P = 0.057). The percentage of Bb phenotype carriers was significantly lower in the PBC patients than in the healthy controls (5.2% vs. 17.5%, P = 0.021) and. the percentage of bb phenotype carriers was significantly higher in the PBC patients than in the healthy controls (94.8% vs. 80.6%, chi(2) = 6.52, P = 0.01). We also detected a significant association of the BsmI polymorphisms in PBC patients in comparison with controls (P = 0.01). Furthermore we found the difference in the FokI, BsmI, ApaI, and TaqI genotype distribution between Chinese health controls and Caucasian health controls.
Conclusion: There is a significant association between FokI polymorphism and AIH and a significant association between the BsmI polymorphisms and PBC in Chinese.