Genes link Vitamin D and sunlight to MS
Friday February 6th, 2009
Taking vitamin D during pregnancy may be important in lowering the risk of a child developing multiple sclerosis, according to a genetic study published yesterday.
Vitamin D deficiency may alter the baby's genes making it susceptible to this disease, say Professor George Ebers of Oxford University, UK, and colleagues. And "growing evidence implicates sunlight or vitamin D as a key environmental factor" in the condition.
The link between sunlight and the disease has been known about for some time as it is more common in countries close to the North Pole than in those close to the equator.
Multiple sclerosis has a complex genetic basis, they write in the journal PLoS Genetics. One major risk factor is variation in a certain region on chromosome six, known as DRB1*1501. People carrying a single copy of the variant are at a higher risk, and the risk is higher still for those with two copies - one in 100, rather than one in 1,000 for the general population.
The team found a direct relationship between vitamin D and this genetic variant. Proteins activated by vitamin D bind to a particular DNA sequence lying next to the DRB1*1501 variant, switching the gene on, they explain.
Professor Ebers says: "We have known for a long time that genes and environment determine multiple sclerosis risk. Here we show that the main environmental risk candidate - vitamin D - and the main gene region are directly linked and interact. If too little vitamin D is available, the gene may not function properly."
Professor Ebers has previously shown that environmental changes to the same gene region can be inherited - an "epigenetic effect".
"Epigenetics will have important implications, not only for multiple sclerosis, but for other common diseases," he says. "For mothers, taking care of their health during their reproductive years may have beneficial effects on the health of their future children or even grandchildren."
Ramagopalan, S. V. et al. Expression of the Multiple Sclerosis-Associated MHC Class II Allele HLA-DRB1*1501 Is Regulated by Vitamin D. PLoS Genetics, Vol. 5(2): e1000369. doi:10.1371/journal.pgen.1000369
Tags: Brain & Neurology | Child Health | Childbirth and Pregnancy | Genetics | Nutrition & Healthy Eating | UK News