Objective: To explore the polymorphisms of vitamin D receptor (VDR) gene Tru I polymorphisms and the influence of this variation on Bsm I polymorphisms in Han nationality.
Methods: Venous blood samples from 80 healthy individuals of Han nationality were collected and genomic DNA was extracted, VDR Bsm I and Tru I were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to analyze the polymorphisms of VDR gene; After using another primers to test VDR Bsm I in the same samples, the consistence of each method was assessed.
Results: The frequencies of the VDR Tru I genotype in the groups were: TT 68.7%, Tt 26.3%, tt 5.0%; VDR Bsm I were: BB 6.2%, Bb 52.5%, bb 41.3%; Both polymorphisms were under Hardy-Weinberg equilibrium. After using another pair of primer, the frequencies of Bsm I genotype were BB 20.0%, Bb 26.2%, bb 53.8%, 22 genotype Bb changed to genotype BB or genotype bb in comparison with the result of first detection.
Conclusion: The VDR Tru I polymorphism is found in the Han nationality, the distribution of this site's polymorphism is different from that of other nationalities. The presence of Tru I variation can result in some allele of Bsm I genotype drop-out in some study.