Parent-of-origin effect in multiple sclerosis: observations from interracial matings.
BACKGROUND
Multiple sclerosis (MS) is a complex neurologic disease with a striking geographical distribution. In Canada, prevalence is high in Caucasians of Northern European ancestry and uncommon in North American Aboriginals, many of whom now have Caucasian admixture.


METHODS
The population-based Canadian Collaborative Project on the Genetic Susceptibility to MS provided the characteristics of 58 individuals with 1 Caucasian and 1 North American Aboriginal parent from a database of 30,000 MS index cases.


RESULTS
We found that MS index cases with a Caucasian mother and a North American Aboriginal father had a higher sib recurrence risk and greater F:M sex ratio (p = 0.043) than patients with a North American Aboriginal mother and Caucasian father.


CONCLUSIONS
Maternal parent-of-origin effects in multiple sclerosis disease etiology previously seen in studies of half-siblings and avuncular pairs are also seen in Caucasian-North American Aboriginal admixture matings and warrant further investigation. A differential influence of maternal risk transmission on the sex ratio of affected offspring is implied. The method of analysis used may have broader implications for detection of parent-of-origin effects in admixture cohorts.
Ramagopalan
S V
SV
Wellcome Trust Centre for Human Genetics, University of Oxford, Headington.
Yee
I M
IM
Dyment
D A
DA
Orton
S-M
SM
Marrie
R A
RA
Sadovnick
A D
AD
Ebers
G C
GC
D000328:Adult; D002170:Canada / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000235:genetics*; D010290:Parents; D012737:Sex Factors; D011795:Surveys and Questionnaires; D044465:White People / Q000235:genetics*