维生素D受体基因多态性与0~6岁汉族儿童骨密度关系的研究

目的研究维生素D受体基因多态性与0~6岁汉族儿童骨密度(BMD)的关系，为临床儿童低BMD的早期预防提供理论依据。方法上海新华医院上海市儿科医学研究所2002年7月至2004年3月收集排除影响骨代谢疾病的上海地区0~6岁汉族儿童204例，进行问卷调查、体格测量；用原子吸收分光光度计测血清锌；用放射免疫法测血清25(OH)D3；用超声BMD仪测定胫骨中段骨密度；用聚合酶链反应 限制性片段长度多态性方法，分析4个限制性酶切位点(ApaI、TaqI、BsmI、FokI)的多态分布。用多因素协变量方差分析维生素D受体(VDR)基因多态性与BMD的关系。结果多因素协方差分析消除血清25(OH)D3水平、血清锌水平、户外体育活动等因素对BMD的影响后，发现VDR基因BsmI酶切位点等位基因型和FokI酶切位点等位基因型与BMD相关，Bb基因型的BMD百分位数明显低于bb基因型，分别为2200%和4314%，差异有显著性(F=504,P<005)；ff基因型骨密度低于Ff与FF基因型，分别为2697%、3795%、5352%，差异有极显著性(F=811,P<0001)。而在Apa I、Taq I酶切位点，不同等位基因型与BMD无关(F=108、127，P>005)。结论VDR基因在BsmI、FokI酶切位点的多态性与0~6岁汉族儿童BMD相关。

Reseach on the relation between vitamin D receptor gene polymorphism and bone mineral density among the 0 6 years old Han children.

AbstractObjectiveTo explore the relation between vitamin D receptor(VDR) gene polymorphism and bone mineral density(BMD) of Han children aged 0~6 years,and to offer the foundation for the early prevention of clinically low BMD among children.Methods204 0~6 year old Han children without bone metabolism disease were randomly selected.Questionnaire investigation and physical measurement of height and weight were done.Serum zinc measured.by the atomic absorption spectrum instrument.Serum 25(OH)D3 measured by radio immunity.The BMD of middle point at the tibia measured with ultrasonic bone density instrument.VDR gene polymorphism(cleavaged by restriction endonuclease of ApaI，TaqI，BsmI，FokI) analyzed by PCR RFLP.The association between the VDR genetic polymorphism and BMD was made by the statistical method of univarience analysis.ResultsWhen the influence of such factors as serum 25(OH)D3,serum zinc and out door activities on bone density was removed,the gene types of BsmI and FokI were found apparently related to bone density.The bone density of the Bb genotype showed a much lower percentage than that of bb genotype with an obvious difference (P<005) correspondently shown from 2200% to 4314%,while the bone density of the ff genotype is even lower than that of genoype Ff and genotype FF with an extremely obvious difference (P<0001) correspondently shown in their percentage of 2697%,3795% and 5352%.In locus on Apa I and Taq I,the genotypes of the alleles showed no association with bone density.ConclusionThe VDR gene polymorphism in the site cleavaged by restriction endonuclease of BsmI，FokI is related to the BMD of Han children aged 0~6 years.