ScienceDaily (Jan. 26, 2012) — For
years it was thought that a difficult birth and other perinatal
factors were the leading causes of cerebral palsy (CP), a group
of disorders that can involve brain and nervous system
functions such as movement, learning, hearing, seeing and
thinking. Now, researchers at Geisinger Health System find that
the majority of cerebral palsy causes may in fact be caused by
genetic abnormalities.
Published in the The Lancet Neurology, Geisinger
researchers find that CP -- the most common physical disability
of childhood -- is probably caused by multiple genetic factors,
similar to other neurodevelopmental disorders such as autism
and intellectual disability. The paper suggests physicians
should consider performing genetic testing when children
present with CP and CP-like conditions.
"There is a widespread misconception that most cases of CP are
caused by difficult delivery leading to birth asphyxia," said
Andres Moreno De Luca, M.D., research scientist at the Genomic
Medicine Institute, Geisinger Health System, and lead author of
the paper. "What we're finding is a growing body of evidence
that suggests mutations in multiple genes are responsible for
CP. In fact, we suspect these genetic abnormalities may also be
the cause of some difficult births to begin with."
Despite substantial improvements in obstetric and neonatal
care, the paper finds the worldwide prevalence of cerebral
palsy has remained stable at 2 to 3 per 1,000 livebirths for
more than 40 years. Inadequate oxygen supply to fetuses, known
as birth asphyxia, remains the most studied factor associated
with CP, though electronic fetal monitoring and other
technologies have been developed to detect fetal distress.
"What we're finding is even though more preventative efforts
have been put in place, like fetal monitoring, the incidence of
CP has not decreased," said David Ledbetter, Ph.D., chief
scientific officer, Geisinger Health System. "We've seen a
five-fold increase in the rate of caesarean sections, which are
done in part to avoid potentially difficult delivery, and
again, the CP rates remain steady. These findings lead us to
believe genetics play a much bigger role than previously
thought."
The paper also reports that even though most cases of CP are
not caused by birth asphyxia and those that are can rarely be
prevented by obstetric intervention, between 1999 and 2003 an
estimated 76 percent of obstetricians in the U.S. faced medical
malpractice litigation, most often for alleged birth
mismanagement resulting in CP.
"We now know of six genes that can cause CP when disrupted, and
we estimate that many other developmental brain genes probably
contribute to the genetic heterogeneity of this disorder," said
Dr. Moreno De Luca. "Many capable obstetricians face legal
action even though research is telling us genetics is the
likely cause of most cases of CP."
As the paradigm shift continues and more researchers,
clinicians, and the general population start to consider the
cerebral palsies as a group of neurogenetic disorders, the
paper states we will probably witness an increase in research
efforts, a change in the diagnostic approach, and eventually
novel therapies for treating CP.
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The above story is reprinted[1] from
materials[2] provided
by Geisinger Health System[3], via
Newswise[4].Note: Materials may be edited for content and length. For
further information, please contact the source cited
above.
Journal Reference:
- Andres Moreno-De-Luca, David H Ledbetter, Christa L Martin.
Genomic insights into the causes and classification of
the cerebral palsies. The Lancet Neurology,
2012; DOI: 10.1016/S1474-4422(11)70287-3[5]
Note: If no author is given, the source is cited
instead.
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