Multiple sclerosis risk changes with the season

Jan 29, 2010

Previous studies have shown multiple sclerosis (MS) patients are more often born in spring than in any other season, indicating that there is an environmental risk factor for the disease. A paper in the journal Neurology, reviewed for f1000 Medicine by Emmanuelle Waubant and Ellen Mowry, now suggests that this seasonal effect is mediated by the gene HLA-DRB1.

In many European populations, the HLA-DRB1*15 allele of this gene is associated with an increased risk of MS, and the large-scale study of MS patients from Canada, Sweden and Norway now shows that this allele is more common among patients born in the spring.

Waubant and Mowry said the study was "unique in its attempt to understand how genes and environment interact in MS". However, even though there is a correlation between birth month, genetics and risk of MS, it is not yet clear how this is regulated.

One likely contender is , which influences expression of the HLA-DRB1*15 allele. Since vitamin D production fluctuates with the seasons, a vitamin D deficit in pregnant mothers could be related to the increased risk of MS among spring births, but this requires further investigation.

Waubant and Mowry said the study may influence preventative and therapeutic treatments through the understanding of environmental risks and their interaction with relevant genotypes.

Previous studies by the Neurology paper's authors showed that in people who carry the , a lack of vitamin D during early life might impair the ability of the thymus to delete rogue , which then go on to attack the body, leading to a loss of on the nerve fibres.

Study author Dr Sreeram Ramagopalan said that taking vitamin D supplements during pregnancy may reduce the risk of a child developing MS in later life. Government guidelines also recommend that children under five take daily vitamin D supplements.

Explore further: French firm announces multiple sclerosis drug breakthrough

More information: The full text of this article is available free for 90 days at www.f1000medicine.com/article/xy02t4j40r2slgt/id/1387957

Related Stories

Prescribing sunshine for multiple sclerosis?

May 26, 2009

Could a holiday in the sun reduce the risk of developing multiple sclerosis? In a recent review for F1000 Medicine Reports, Bridget Bagert and Dennis Bourdette highlight recent advances in potential treatments.

Childhood sun exposure may lower risk of MS

Jul 23, 2007

People who spent more time in the sun as children may have a lower risk of developing multiple sclerosis (MS) than people who had less sun exposure during childhood, according to a study published in the July 24, 2007, issue ...

Recommended for you

Study sheds new light on brain's source of power

Apr 24, 2015

New research published today in the journal Nature Communications represents a potentially fundamental shift in our understanding of how nerve cells in the brain generate the energy needed to function. The st ...

New insight into how brain makes memories

Apr 24, 2015

Every time you make a memory, somewhere in your brain a tiny filament reaches out from one neuron and forms an electrochemical connection to a neighboring neuron.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.