The course of chronic lung diseases in children in terms of VDR gene FokI polymorphism

Background. Chronic non-specific lung diseases (CNSLDs) in children are considered an important medical and social problem. Hereditary lung diseases are basically associated with certain genetic mutations in certain chromosomal loci, and their course and outcomes are largely dependent on genetic predictors encoding the system of cellular proteinases, surfactant and vitamin D receptors (VDR). The influence of VDR gene polymorphisms (BsmI, FokI, TaqI, ApaI) on the risk and development of chronic allergic diseases of the lungs and COPD has been established. Objective. Evaluation of the phenotypic effect of VDR gene FokI polymorphism on the course of CNSLDs in children. Methods. The main cohort consisted of 98 children with CNSLDs divided into 2 subgroups. The group1 was composed of children with CNSLDs formed on initially healthy lung tissue (chronic bronchitis, obliterating bronchiolitis; n=42). The group 2 was represented by patients with secondary CNSLDs, namely cystic fibrosis (n=34), immunodeficiencies (n=12) and pulmonary malformations (n=10). The control group consisted of 93 conditionally healthy children. The molecular genetic testing of the VDR gene FokI was carried out by polymerase chain reaction and restriction fragment length polymorphism. Results. According to statistical analysis, significant differences were found in the frequency of various polymorphic variants of the VDR gene FokI between the main and control groups. There were no significant associations between the polymorphic variants of the VDR gene FokI and the frequency, severity of exacerbations, severity of respiratory failure, and the nature of the microbiota of the airways between patients with primary and secondary CNSLDs. The results of statistical analysis indicate a significant prevalence of the F/F genotype in children with mild obstructive and restrictive changes (not more than 80% of the normal values), and the dominance of genotypes containing the mutant f allele in patients with moderate decrease in vital lung capacity and forced expiratory volume in subgroup 2. Conclusion. No pronounced phenotypic effect of VDR gene FokI polymorphism on the course of CNSLDs in children was found. Possibly, the phenotypic effect of VDR gene FokI polymorphism is realized at an older age, which necessitates the continuation of this study in a cohort of adult patients.

FokI, chronic non-specific lung diseases, children, polymorphism, FokI, vitamin D receptor