# Genetic Aspects of Bone Remodelling in Children under One Year of Age in the Kazakh Population

## TL;DR

This study explores how genetic variations in the VDR and RANKL genes affect bone health in young Kazakh children, linking them to vitamin D levels and bone density.

## Contribution

The study identifies specific genetic polymorphisms in the Kazakh population that correlate with vitamin D deficiency and reduced bone density in infants.

## Key findings

- 78% of infants showed reduced vitamin D levels, especially in the 7-12 month age group.
- Certain RANKL and VDR gene variants are associated with lower bone density and vitamin D deficiency.
- VDR gene genotypes T/T and C/T show a strong link to vitamin D levels below the normal range.

## Abstract

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.

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.

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.

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.