最終身長

成長

軟骨細胞

ビタミンD受容体

The function of 1, 25 D_3 in bone development is to regulate the differentiation or proliferation of osteoblastic, osteoclastic and chondrocytic lineage. An A (T/C) G substitution exists in the first of two putative translation initiation sites in exon 2 of VDR gene. We examined the significance of this polymorphism. We studied the relationship between height, BMD and exon 2 polymorphism in ninety healthy Japanese females aged 18-20 yr, 159 healthy Japanese aged 13 yr and 24 normal short children aged 6-10 yr less than -1.5SD in height. BMD was determined by dual energy X-ray absorptiometry. Exon 2 polymorphism was analyzed by PCR-SSCP, and/or PCR-direct sequencing and PCR-RFLP. In 49 women aged 18-20 yr, blood and urine were collected for biochemical analysis. The frequency of exon 2 polymorphism was genotype CC (ACG/ACG), 0.37; CT (ACG/ATG), 0.51; and TT (ATG/ATG), 0.12. The mean height of subjects with the CT was taller in 18-20 yr and 13 yr groups. CT was less frequent in short children. There was no significant difference in lumbar spine BMD between genotypes. Subjects with CC showed lower femoral neck BMD. TT had lower parathyroid hormone levels. In conclusion, the exon 2 polymorphism of the VDR gene is one of the major determinants of height.