Mutations in the Vitamin D Receptor Gene in Four Patients with Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets
November 2008
in “
Arquivos Brasileiros de Endocrinologia & Metabologia
”
TLDR Four patients with a type of rickets and hair loss had different mutations in their vitamin D receptor gene, causing it to not work properly.
In a study from 2008, researchers investigated mutations in the vitamin D receptor (VDR) gene in four Brazilian children who presented with hereditary 1,25-dihydroxyvitamin D-resistant rickets and alopecia. They amplified and sequenced the coding region of the VDR gene, identifying three distinct mutations: two patients shared a mutation at amino acid position 259 in exon 7 (p.Q259E), one patient had a mutation at codon 319 in exon 8 (p.G319V), and another had a mutation in exon 3 that resulted in a truncated protein at position 73 (p.R73X). Functional studies using fibroblast primary cultures from the patients' skin biopsies, treated with increasing doses of 1,25(OH)2 vitamin D, revealed that the mutant VDRs were unable to be properly activated, leading to a reduction in 24-hydroxylase expression level.
