MS is a complex disease where both genetics and environment seem to play a role. Canadian researchers Dr. Dessa Sadovnick from the University of British Columbia and Dr. George Ebers, of Oxford (formerly of the University of Western Ontario), participated with a group of international investigators to examine genetic aspects of this proposed interaction. The results of this study show an association between the month of birth, the presence of a specific genetic variant (associated with a higher risk of MS) and the risk of developing MS, suggesting a possible interaction of a seasonal risk factor with a genetic risk factor in the development of this disease. Neurology. 2009 Dec 15;73(24):2107-11.
Details
Multiple sclerosis (MS) displays a month-of-birth effect, with more individuals being born in the spring and fewer in the winter. This effect was shown to be more pronounced in familial cases of MS. In the present study, researchers investigated whether this month-of-birth association has any relation to the principal MS susceptibility gene, HLA-DRB1.
A total of 4,834 patients with MS, 4,056 controls, and 659 unaffected siblings from Canada, Sweden, and Norway were genotyped for the HLA-DRB1 gene. Month of birth was compared for patients, controls, and unaffected siblings with and without the MS risk allele HLA-DRB1*15.
Significantly fewer patients with MS carrying the HLA-DRB1*15 risk allele were born in November compared with patients not carrying this allele and the difference was found to be statistically significant. Additionally, patients with MS carrying HLA-DRB1*15 had a higher number of April births compared with patients with MS not carrying HLA-DRB1*15, again achieving statistical significance. These differences were not present in controls or unaffected siblings.
Researchers concluded that month of birth, HLA-DRB1 genotype, and risk of multiple sclerosis are associated. The interaction of a seasonal risk factor with loci at or near HLA-DRB1 during gestation or shortly after birth is implicated.
National Research and Programs
Offert en français.
Disclaimer
The Multiple Sclerosis Society of Canada is an independent, voluntary health
agency and does not approve, endorse or recommend any specific product or therapy,
but provides information to assist individuals in making their own decisions.
