Abstract
BACKGROUND: This study investigates genetic markers, such as polymorphisms in the vitamin D receptor (VDR) and receptor activator of nuclear factor-kappa B ligand (RANKL) genes, to determine if they can serve as prognostic indicators for the development of bone-tissue pathologies in childhood. MATERIAL AND METHODS: The study included 104 healthy children aged from birth to 12 months. Genetic testing was conducted to identify polymorphisms in the VDR and RANKL genes. RESULTS: 78% of the 104 children from the Kazakh population showed a decrease in the level of vitamin D, with particularly promising results in infants seven to 12 months old. Indicators of total calcium and phosphorus in children were uninformative for bone-metabolism analysis. The homozygous C/C type according to RANKL rs9594759 was detected in 17% of children; the homozygous T/T variant according to RANKL rs9594738 was detected in 28%; the homozygous T/T according to VDR rs2228570 was detected in 17%; and the homozygous A/A according to VDR rs2228570 was detected in 4%. These variant polymorphisms are associated with reduced bone density. RANKL rs9594738 and RANKL rs9594759 have shown a moderate connection with vitamin D serum concentration. CONCLUSION: A relatively strong relationship was found between the T/T and C/T genotypes of the VDR gene and the concentration of vitamin D falling below the norm, and there is a direct relationship between vitamin D levels and bone pathology risk in children.