Sainz J, Van Tornout J M, Loro M L, Sayre J, Roe T F, Gilsanz V
Department of Radiology, Children's Hospital of Los Angeles, CA 90027, USA.
N Engl J Med. 1997 Jul 10;337(2):77-82. doi: 10.1056/NEJM199707103370202.
Bone mass is under strong genetic control, and recent studies in adults have suggested that allelic differences in the gene for the vitamin D receptor may account for inherited variability in bone mass. We studied the relations of the vitamin D-receptor genotype to skeletal development and variation in the size, volume, and density of bone in children.
We identified three allelic variants of the vitamin D-receptor gene using the polymerase chain reaction and three restriction enzymes (ApaI, BsmI, and TaqI) in 100 normal prepubertal American girls of Mexican descent. We then determined the relations of the different vitamin D-receptor genotypes (AA, Aa, aa, BB, Bb, bb, TT, Tt, and tt) to the cross-sectional area, cortical area, and cortical bone density of the femoral shaft and the cross-sectional area and density of the lumbar vertebrae.
The vitamin D-receptor genotype was associated with femoral and vertebral bone density. Girls with aa and bb genotypes had 2 to 3 percent higher femoral bone density (P=0.008 and P=0.04, respectively) and 8 to 10 percent higher vertebral bone density (P=0.01 and P=0.03, respectively) than girls with AA and BB genotypes. There was no association between the cross-sectional area of the vertebrae or the cross-sectional or cortical area of the femur and the vitamin D-receptor genotype. The chronologic age, bone age, height, weight, body-surface area, and body-mass index did not differ significantly among girls with different vitamin D-receptor genotypes.
Vitamin D-receptor gene alleles predict the density of femoral and vertebral bone in prepubertal American girls of Mexican descent.
骨量受强大的基因控制，近期针对成年人的研究表明，维生素D受体基因的等位基因差异可能是骨量遗传变异性的原因。我们研究了维生素D受体基因型与儿童骨骼发育以及骨骼大小、体积和密度变化之间的关系。
我们使用聚合酶链反应和三种限制性内切酶（ApaI、BsmI和TaqI），在100名墨西哥裔美国青春期前正常女孩中鉴定了维生素D受体基因的三种等位基因变体。然后我们确定了不同维生素D受体基因型（AA、Aa、aa、BB、Bb、bb、TT、Tt和tt）与股骨干的横截面积、皮质面积和皮质骨密度以及腰椎的横截面积和密度之间的关系。
维生素D受体基因型与股骨和椎骨骨密度相关。与AA和BB基因型的女孩相比，aa和bb基因型的女孩股骨骨密度分别高2%至3%（P分别为0.008和0.04），椎骨骨密度分别高8%至10%（P分别为0.01和0.03）。椎骨的横截面积、股骨的横截面积或皮质面积与维生素D受体基因型之间没有关联。不同维生素D受体基因型的女孩在年龄、骨龄、身高、体重、体表面积和体重指数方面没有显著差异。
维生素D受体基因等位基因可预测墨西哥裔美国青春期前女孩的股骨和椎骨骨密度。
