Editor's Note: Following the 67th American Academy of Neurology (AAN) Annual Meeting, Medscape interviewed Fred D. Lublin, MD, about genetic advances in multiple sclerosis (MS) and their clinical implications, along with research that he presented at the meeting.
Medscape: Can you speak to the known genetic contributions to MS? Specifically, how many genetic variants associated with MS have been identified?
Dr Lublin: While more than 150 loci conferring susceptibility to MS have been identified, each provides only a small increase in risk and none is known to be required.
Medscape: How much weight does genetic influence have in the etiology of MS compared with environmental factors?
Dr Lublin: Both genetic and environmental factors are important in determining the risk for MS; the proportion of each is not yet known. The clearest environmental risk factor for MS is smoking, but how it directly affects the illness is unclear. Vitamin D has an association with MS and interesting genetic and immunologic actions, but a direct connection to MS pathogenesis has not yet been found. Childhood obesity also has a link with MS, but again, there is no clear mechanism to explain the association.
Medscape: How does the gastrointestinal (GI) microbiome appear to contribute to MS? I imagine that the biome is subject to genetic and environmental factors as well.
Dr Lublin: The GI microbiome may play an important role in MS, as the gut is a major interface for microbes and the immune system. Further research is needed to determine the exact role of these interactions, and one should keep in mind that there are other microbiomes that could be important, such as pulmonary.
Medscape: Tell us about the CombiRx data that you presented at AAN this year.
Dr Lublin: At AAN this year, we presented our first look at potential genomic markers of disease course, identifying two loci that, if confirmed, might represent markers of disease activity.
Medscape: Are there any clinical implications of the findings for the practicing physician?
Dr Lublin: It is too early to determine the implications as yet; we are searching for genetic markers that will inform our understanding of the MS disease course and severity. If we can accomplish this, we could utilize such information in determining treatment algorithms.
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Cite this: 5 Quick MS Questions Answered - Medscape - May 06, 2015.