VDR (vitamin D receptor)

FokI · BsmI · ApaI · TaqI

VDR encodes the receptor through which the active form of vitamin D exerts its effect in the cell. Several common variants slightly change receptor amount or mRNA stability. Associations with bone, the immune system and autoimmunity are described, but mostly weak and inconsistent.

The four classical markers

FokI lies in the start region and decides whether translation begins at the first or a slightly later start codon; from this follow the protein variants F (short, more active) and f (long). BsmI, ApaI and TaqI lie in the 3′ region, do not change the amino acid sequence directly (TaqI is synonymous), but form linked haplotypes that can influence mRNA stability.

What it means in the vitamin D context

The VDR variants modulate how strongly a cell responds to available vitamin D. They do not, however, replace measuring 25-OH-D in blood, which shows the actual supply status. Genotype and level answer different questions: sensitivity versus amount.

Context

Despite hundreds of studies the VDR associations remain weak and differ by population. Individual genotypes should not be over-interpreted. Genome shows the markers as technical evidence.

What Genome measures. The genotypes at the VDR markers rs2228570 (FokI), rs1544410 (BsmI), rs7975232 (ApaI) and rs731236 (TaqI).

Related topics

GC (vitamin D binding protein)MTHFRrsIDs, microarray and SNP lookup

Sources

  1. 1Uitterlinden et al., 2004 Genetics and biology of vitamin D receptor polymorphisms. Gene 338:143–156. doi.org/10.1016/j.gene.2004.05.014
  2. 2Valdivielso & Fernandez, 2006 Vitamin D receptor polymorphisms and diseases. Clinica Chimica Acta 371:1–12. doi.org/10.1016/j.cca.2006.02.016