Background: Amyotrophic lateral sclerosis (ALS) patients manifest aberrations in the vitamin D endocrine system, with a vitamin D deficiency. Genetic investigations have identified those proteins which link vitamin D to ALS pathology: major histocompatibility complex class II molecules, toll-like receptors, poly(ADP ribose) polymerase-1, haeme oxygenase-1, the reduced form of nicotinamide adenine dinucleotide phosphate and calcium-binding proteins. Vitamin D additionally impacts ALS through cell-signalling mechanisms: glutamate, matrix metalloproteinases, the Wnt/β-catenin signalling pathway, mitogen-activated protein kinase pathways, prostaglandins, reactive oxygen species and nitric oxide synthase, but its role has been only poorly investigated.
Objective: Our aim was to investigate vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in an ALS population. This gene encodes the nuclear hormone receptor for vitamin D3.
Materials and methods: A total of 75 consecutive sporadic ALS patients (~20% of the Hungarian ALS population) and 97 healthy controls were enrolled to investigate the possible effects of the different VDR alleles. A restriction fragment length polymorphism technique was utilized for allele discrimination.
Results: One of the four investigated SNPs was associated with the disease, but none of the alleles of these SNPs influenced the age at disease onset. The ApaI A allele was more frequent in the ALS group than in the control group and may be an ALS risk factor.
Conclusions: This is the first verification of the genetic link between ALS and VDR. However, further studies are needed to confirm these findings.
Keywords: ApaI; amyotrophic lateral sclerosis; neurogenetics; vitamin D receptor gene.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.