Association of vitamin D binding protein polymorphisms with bronchopulmonary dysplasia: a case–control study of gc globulin and bronchopulmonary dysplasia

The pathophysiologies of bronchopulmonary dysplasia (BPD) are inflammation, infection, tissue damage, angiogenesis defects and genetic susceptibility. Because of the role of the vitamin D binding protein (Gc globulin) on these factors, we investigated the relationship between Gc globulin polymorphisms and BPD. This case-control study was performed with 160 neonates (⩽32 gestational ages, ⩽1500 g). PCR DNA sequence analyses were used for GC gene rs4588 and rs7041 single-nucleotide polymorphisms. In the univariate analyses, it was observed that Gc2 was the only variant that was protective against BPD (Odd ratio (OR)=0.47, 95% coinfidence interval (CI)=0.24 to 0.89, P=0.020). In the multivariate analyses, Gc2 decreased the risk of disease (OR=0.15, 95% CI=0.029 to 0.79, P=0.026) independent of gestational age, birth weight, 5-min Appearance, Pulse, Grimace, Activity, and Respiration scores, respiratory distress syndrome and sepsis. The Gc2 variant was, after adjusting for confounders, associated with a decrease in the frequency of BPD. Our study adds Gc globulin to the list of candidate genes that potentially contribute to the etiology of the disease.