Early life child exposure and the risk of multiple sclerosis: a population based study.
Ramagopalan SV., Guimond C., Dyment DA., Yee IM., Ebers GC., Sadovnick AD.
The precise aetiology of multiple sclerosis (MS) is yet to be conclusively determined, but both genes and environment and interactions thereof are important. It has been suggested that early life child exposure influences MS susceptibility. Here, in a population-based cohort, we investigated whether infant day care attendance influences the subsequent risk to develop MS. We identified 379 MS index cases and 101 spousal controls, all of whom were a single child (i.e. they had no biological sibs, half-sibs, step-sibs, adopted sibs) from the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS). Frequency of infant day care attendance was compared for index cases and controls and the results were not statistically significant. Exposure to other infants during early childhood thus does not appear to be a risk factor for MS.