PARIS - Cerebral palsy, a disability of the brain linked to problems in pregnancy or birth, may have an inherited cause, according to a study published on Wednesday.
Norway researchers found that families where a close relative has cerebral palsy are at increased risk of giving birth to a child with this condition.
The investigators trawled through a top-quality database covering the health of Norwegians born between 1967 and 2002.
In absolute terms, the risk of having a child with cerebral palsy was very low, they found.
Out of 2.03 million people born during this period, 3,649 were diagnosed with condition.
But in families where a child had cerebral palsy, there was six- to nine-fold increased risk that the following full sibling - meaning, a first-degree brother or sister - would also be born with it, compared to families with no history of the disability.
There was an up to three-fold risk for a half sibling, or second-degree relative, according to the probe.
But for people with an affected first cousin - a third-degree relative - the increased risk fell, to 1.5 times.
Parents affected by cerebral palsy carried a sixfold risk of having an affected child compared to unaffected parents.
The risks were seen even after pre-term births, an important factor in cerebral palsy, were stripped out of the calculations.