汉族人维生素D受体基因TruⅠ酶切位点多态性及其对BsmⅠ酶切位点多态性测定的影响

The vitamin D receptor gene Tru Ⅰ polymorphisms and its effect on the detection of Bsm Ⅰ polymorphisms in Han nationality

目的测定汉族人维生素D受体基因TruⅠ酶切位点多态性分布并探讨其对BsmⅠ酶切位点多态性分布测定的影响。方法收集80名健康汉族人外周静脉血标本,提取基因组DNA,用限制性片段多态性长度酶切法测定80名汉族人维生素D受体基因TruⅠ、BsmⅠ酶切位点多态性;换用常规引物再次测定上述标本BsmⅠ酶切位点多态性;分析维生素D受体基因TruⅠ、BsmⅠ酶切位点多态性及两次测定的BsmⅠ位点的一致性。结果测得TruⅠ基因型频率为TT68.7%,Tt26.3%,tt5.0%;同一PCR片段上测得BsmⅠ位点基因型频率为BB6.2%,Bb52.5%,bb41.3%,多态性分布均符合Hardy-Weinberg平衡;换用常规引物测定同批标本BsmⅠ位点多态性,基因型分布为BB20.0%,Bb26.2%,bb53.8%,不符合Hardy-Weinberg平衡（r=13.29,P〈0.01）。与第1次测定相比,有22个标本基因型由Bb型变成BB型或bb型,发生基因型丢失。结论汉族人VDR基因存在TruⅠ多态性,其多态性分布与其它种族不同;TruⅠ酶切位点多态性可引起BsmⅠ位点多态性测定时等位基因的丢失。

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 genome 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 ofthe VDR Tru Ⅰ genotype in the groups were： TT68.7%,Tt26.3%,tt5.0%; 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.