Relationship between vitamin D receptor gene polymorphism and bone mineral density in children

Objective To investigate the relationship between vitamin Dreceptor(VDR)gene polymorphism and bone mineral density(BMD).Methods 213 children aged 6～10 years were randomly selected in Xishui county of Hubei province.Questionnaire investigation and physical measurement of height were done.BMD was determined by dual energy x-ray absorptiometry at distal forearm.The distribution of vitamin Dreceptor gene FokI promoter polymorphism was analyzed with polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).Results The frequency of FokI VDR gene polymorphism was 25.8% for FF,62.0% for Ff and 12.2% for ff.There was no statistical difference in frequency distribution of genotypes and alleles between male and female(P>0.05).Subjects with the FF genotype had the highest weight,BMI,BMD and serum calcium levels.The Ff genotype had the highestheight.No statistical differences was found in serum phosphorus and alkaline phosphatase among genotypes(P>0.05).The BMD of children with FF genotype was higher than those with the Ff genotype and ff genotype had an intermediate BMD.There was statistical difference of BMD in three genotypes(P<0.01).Statistically differences existed in serum levels of Ca in three genotypes among girls(P<0.05).Conclusion The FokI polymorphism of the VDR receptor affects the development of BMD in children.