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Published on: December 9, 2015
A timing-of-birth effect on multiple sclerosis clinical phenotype
A D Sadovnick1, P Duquette, B Herrera
1Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada. sadovnik@infinet.net
Background:
A month-of-birth (MOB) effect has been shown in multiple sclerosis (MS).
Methods:
Our chi(2) analyses looked at whether this MOB effect differed by MS phenotype ("bout onset," "primary progressive").
Results:
The MOB effect was derived from "bout onset" MS patients (May/November ratio = 1.43; chi(2) = 17.32, df = 1, p = 0.000032).
Conclusions:
An unspecified environmental effect in early development can influence both multiple sclerosis susceptibility and phenotype.
Insights
The month-of-birth (MOB) effect influences multiple sclerosis (MS) susceptibility and disease type. This environmental factor in early development impacts MS, particularly the "bout onset" phenotype.
Area of Science:
- Neurology
- Environmental Epidemiology
Background:
- A month-of-birth (MOB) effect is a known factor in multiple sclerosis (MS) etiology.
- This effect suggests environmental influences during early development may play a role in MS.
Purpose of the Study:
- To investigate if the month-of-birth effect on multiple sclerosis (MS) risk differs between MS phenotypes.
- Specifically examining differences between "bout onset" and "primary progressive" MS.
Main Methods:
- Chi-squared (chi2) analyses were employed to compare the month-of-birth effect across different MS phenotypes.
- The study focused on analyzing birth month data for patients with "bout onset" and "primary progressive" multiple sclerosis.
Main Results:
- The month-of-birth effect was statistically significant in "bout onset" multiple sclerosis patients.
- A notable difference was observed in the May/November birth ratio (1.43) for this group, with high statistical significance (p = 0.000032).
Conclusions:
- An unidentified environmental influence during early development appears to affect both the likelihood of developing multiple sclerosis (MS) and its clinical presentation.
- This suggests that timing of environmental exposures in relation to birth month is a critical factor in MS pathogenesis.
