维生素D受体多态性与晚发性佝偻病易感性研究

目的研究维生素D受体基因起始密码子（VDRSC）多态性在晚发性佝偻病组、维生素D缺乏状态组及正常对照组中分布频率的差异,探讨晚发性佝偻病的遗传易感因素。方法用聚合酶链反应——限制性长度多态性（RFLP）分析晚发性佝偻病组30例、维生素D缺乏状态组35例以及正常对照组60例VDRSC多态性的分布频率。结果三组VDRSC基因型分布频率差异有统计学意义（χ^2=13．184,P=0．010）;等位基因分布频率差异也有统计学意义（χ^2=8．975,P=0．011）。组间两两比较晚发性佝偻病组VDRSC基因型和等位基因与其他两组比较差异有统计学意义,其FF型频率（56．7％）明显高于正常对照组（21．7％,P=0．006）,也明显高于维生素D缺乏状态组（22．9％,P=0．002）;晚发性佝偻病组F型（70．0％）明显高于正常对照组（48．3％,P=0．006）,也明显高于维生素D缺乏状态组（47．1％,P=0．009）。多项分类Logistic回归分析结果显示,在调整了其他危险因素后,FF型仍是晚发性佝偻病的危险因素,相对危险度（OR）=3．120。结论VDRSC多态性可能决定晚发性佝偻病的遗传易感性。

Association of the vitamin D receptor gene start codon polymorphism with delayed rickets

OBJECTIVE: Delayed rickets is a special type of vitamin D deficiency, the occurrences of delayed rickets mainly relate to vitamin D deficiency, but whether there is hereditary susceptibility of children to development of delayed rickets is unknown. Recently some studies suggest that there is a significant association between vitamin D receptor gene (VDR) polymorphism and the metabolic diseases of bone. The present study aimed to explore the hereditary susceptibility of children to development of delayed rickets through studying the association of the vitamin D receptor gene start codon (VDRSC) polymorphism with delayed rickets. METHODS: The diagnosis was based on clinical, biochemical and radiological data. The subjects were composed of three groups, the patient group had 30 children, the vitamin D deficiency group 35 children, and the control group 60 normal children. The VDRSC genotypes of the three groups were determined by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. RESULTS: There was significant difference in the frequencies distribution of VDRSC genotypes (chi(2) = 13.184, P = 0.010) and VDRSC alleles (chi(2) = 8.975, P = 0.011) among the three groups; the frequency of the FF genotype (56.7%) in the patient group was significantly higher than that in the control group (21.7%, P = 0.006) and that in the vitamin D deficiency group (22.9%, P = 0.002). The frequency of the F alleles in the patient group (70.0%) was significantly higher than that in the control group (48.3%, P = 0.006) and that in the vitamin D deficiency group (47.1%, P = 0.009). Multiple logistic regression analysis showed that FF genotype had a higher risk of delayed rickets (OR = 3.120), indicating that FF genotype may be significantly associated with delayed rickets. CONCLUSION: There is the possibility that the VDRSC polymorphism might be important in determining the hereditary susceptibility of children to development of delayed rickets.