Older siblings in a family are not more likely than younger siblings
to develop multiple sclerosis (MS), a finding that contradicts earlier reports
that suggested a link between early birth-order position and a heightened
risk of developing the disease. The new finding does not support the prediction
of the “hygiene hypothesis” which postulates that children who
are exposed to infections introduced by older siblings are at a reduced risk
of developing MS.
The report of the study’s findings, published online on August
22, will appear in print in the October issue of Lancet
Stephenson J. Birth Order and MS. JAMA. 2005;294(11):1331. doi:10.1001/jama.294.11.1331-d
Customize your JAMA Network experience by selecting one or more topics from the list below.