Seasonal fluctuation of multiple sclerosis births in Sardinia

Study results from different
geographical areas provide
some circumstantial evidence that,
when compared with the general
population, people who later in life
develop multiple sclerosis (MS)
have a pattern of birth excess numbers
in spring and late summer,
which may disclose an association
with MS-predisposing environmental
agents. To identify the presence
of season-related cluster of
MS birth in Sardinia we have designed
a case-control study in the
province of Sassari,Northern Sardinia,
insular Italy, an area at veryhigh
and increasing risk for MS.
Mean birth incidence rate of people
with MS (810 cases) on a threeand
six-months basis were compared
with that of two control populations:
the MS unaffected siblings
(1069), sharing genetic material
with patients, and a representative
number of births (247,612) of the
general population of the study
area.We found that the birth in
months peaking in spring significantly
represents one risk factor for
future MS development. This seasonal
deviation of MS births reveals
an intriguing epidemiological
overlap with common environmental
agents,which may open a
new scenario of hypothetical explanations
for environmental factors
perhaps affecting the CNS at the
crucial time of myelination or
shaping the newborn immune system.