Researchers have found evidence that a direct interaction between vitamin D and a common genetic variant alters the risk of developing multiple sclerosis (MS). The research, published on 6 February in the open-access journal PLoS Genetics, suggests that vitamin D deficiency during pregnancy and the early years may increase the risk of the offspring developing MS later in life.
MS is the most common disabling neurological condition affecting young adults. More than 85,000 people in the UK and 2.5 million worldwide are thought to suffer from the condition, which results from the loss of nerve fibres and their protective myelin sheath in the brain and spinal cord, causing neurological damage.
The causes of MS are unclear, but it has become evident that both environmental and genetic factors play a role. Previous studies have shown that populations from Northern Europe have increased MS risk if they live in areas receiving less sunshine. This supports a direct link between deficiency in vitamin D, which is produced in the body through the action of sunlight, and increased risk of developing the disease.
The largest genetic effect by far comes from the region on chromosome six containing the gene variant known as DRB1*1501 and from adjacent DNA sequences. Whilst one in 1,000 people in the UK are likely to develop MS, this number rises to around one in 300 amongst those carrying a single copy of the variant and one in 100 of those carrying two copies.
Now, in a study funded by the UK's MS Society, the MS Society of Canada, the Wellcome Trust and the Medical Research Council, researchers at the University of Oxford and the University of British Columbia have established a direct relationship between DRB1*1501 and vitamin D.
The researchers found that proteins activated by vitamin D in the body bind to a particular DNA sequence lying next to the DRB1*1501 variant, in effect switching the gene on.<
|Contact: Catriona Silvey|
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