By Shana SagerThe Daily Northwestern
Researchers at Children’s Memorial Research Center, including several professors from Northwestern’s Feinberg School of Medicine, have identified a gene that can increase the likelihood of cerebral palsy in brain-injured children.
Children with the E4 allele of the Apolipoprotein E, or APOE, gene are more likely to develop cerebral palsy following injury to the developing brain. The gene also is associated with an increased risk for Alzheimer’s disease in adults.
“If a baby is born with an E4 allele, then if they undergo some kind of perinatal brain injury, they are more likely to develop cerebral palsy,” said Mark Wainwright, professor of pediatric neurology at Feinberg. “The gene isn’t causing the cerebral palsy. It’s making you at greater risk to develop it, but another injury is needed.”
Cerebral palsy is a non-progressive disorder that results from an injury to the developing central nervous system during the first six weeks to three months of life, said John Sarwark, professor of orthopedic surgery.
Everyone has two of the three alleles of the APOE gene, which produces the apoE protein in the brain. The protein is involved in neural repair, but E4 creates a protein that is less able to regulate brain inflammation following an injury. People with E4 are more likely to have brain damage following an injury and are less capable of repairing it.
Researchers compared the APOE gene in 209 children with cerebral palsy to healthy children of the same gender, race and ethnicity. They found that young children with the E4 allele who suffer a brain injury are more susceptible to developing cerebral palsy.
While the disorder is not expressed the same way in every patient, it most commonly impairs movements such as standing, walking and balancing. Most patients maintain their cognitive functions, Sarwark added, but some may have varying degrees of mental retardation.
Cerebral palsy affects an estimated 500,000 children in the U.S., nearly two in every 1,000 school-aged children.
“A majority of times we don’t know what causes cerebral palsy,” said Maxine Kuroda, professor of pediatrics. “A woman could have an uneventful pregnancy and then the child is born and they start missing their developmental milestones.”
The findings could help doctors identify children who are more susceptible to the disorder following an early-life brain injury.
Children aren’t diagnosed with cerebral palsy until they are two or three years old, so the genetic link could be used to modify treatment of the symptoms through therapy.
“Cerebral palsy is difficult to recognize in a young child and it’s often missed,” Wainwright said. “Doctors also must wait several years to diagnose children with cerebral palsy, to guarantee that it isn’t a progressive condition.”
Kuroda said similar studies must be replicated elsewhere to confirm the findings.
“This was done in Chicago. We don’t know necessarily, say, could this be different in Texas? Could it be different in California?” Kuroda said. “We do have to continue other studies like this in other populations.”
Reach Shana Sager at [email protected].
