[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.