Abstract：
Hypovitaminosis D during infancy is associated with the development of chronic diseases and poor health later in life. While the effect of environmental factors on vitamin D concentration has been extensively explored, this study aimed to explore the effect of genetic factors on vitamin D concentration among Chinese infants. We conducted a multi-centre cross-sectional study in Hong Kong from July 2019 to May 2021. A candidate genetic approach was adopted to study four selected genetic variants of the vitamin D-binding protein (DBP) and vitamin D receptor (VDR) (rs4588, rs7041, rs2282679 and rs2228570) to examine their associations with measured serum 25(OH)D concentration. A total of 378 Chinese infants aged 2-12 months were recruited in this study. Peripheral blood samples were collected from the infants to measure serum 25(OH)D concentration and extract DNA. Results showed that rs7041T and rs2282679C were significantly associated with lower serum 25(OH)D concentration. Further analysis of the DBP variants revealed that the GC1F allele was significantly associated with lower 25(OH)D concentration and identified as the risk DBP isoform in infants. While our results revealed that there is no direct association between VDR-FokI genotype and serum 25(OH)D concentration, a VDR-FokI genotype-specific pattern was observed in the association between DBP isoforms and serum 25(OH)D concentration. Specifically, significant associations were observed in the DBP genotypes GC1F/F, GC1F/2 and GC1S/2 among VDR-FokI TT/TC carriers, but not in VDR-FokI CC carriers. Our findings lay down the basis for the potential of genetic screening to identify high risk of hypovitaminosis D in Chinese infants.
摘要：
婴儿期维生素D缺乏症与慢性疾病的发展和以后的健康状况不佳有关。虽然环境因素对维生素D浓度的影响已被广泛探索，本研究旨在探讨遗传因素对中国婴幼儿维生素D浓度的影响。我们于2019年7月至2021年5月在香港进行了一项多中心横断面研究。采用候选遗传方法研究了维生素D结合蛋白（DBP）和维生素D受体（VDR）的四个选定的遗传变异（rs4588，rs7041，rs2282679和rs2228570），以检查它们与测量的血清25（OH）D浓度的关联。这项研究共招募了378名2-12个月的中国婴儿。从婴儿收集外周血样本以测量血清25（OH）D浓度并提取DNA。结果表明，rs7041T和rs2282679C与较低的血清25（OH）D浓度显着相关。对DBP变异的进一步分析表明，GC1F等位基因与较低的25（OH）D浓度显着相关，并被确定为婴儿DBP同工型的风险。虽然我们的结果表明，VDR-FokI基因型和血清25(OH)D浓度之间没有直接关联，在DBP亚型和血清25(OH)D浓度之间的关联中观察到VDR-FokI基因型特异性模式.具体来说,在DBP基因型GC1F/F中观察到显著关联，VDR-FokITT/TC载波中的GC1F/2和GC1S/2，但不是在VDR-FokICC运营商中。我们的发现为基因筛查确定中国婴儿维生素D缺乏症高风险的潜力奠定了基础。
