Study implicates genetic causes of cerebral palsy

Medical knowledge has historically attributed cerebral palsy (CP) to various environmental stressors—including intrauterine infections, birth defects, and perinatal asphyxia, among others—which result in brain damage in babies. Genetic studies are not routine or recommended in the diagnostic assessment of children with CP.

But a new study indicates that genetic causes may indeed be involved in CP and that they play a much greater role than previously thought. The authors of the study also make the case that genomic testing should now be a routine part of CP diagnosis.

In this study, investigators at The Hospital for Sick Children in Toronto, Canada, and the Research Institute of the McGill University Health Centre (MUHC) in Montreal, performed genomic testing on 115 children with CP and their parents from the Canadian Cerebral Palsy Registry; many of the children had other identified risk factors. The investigators found that about 10% of the children and families carried clinically relevant genetic abnormalities (copy number variations, or CNVs) that explained the etiology of CP or accounted for associated medical complications. Among children in the general population, fewer than 1% have such genetic abnormalities.

“Our research suggests that there is a much stronger genetic component to cerebral palsy than previously suspected,” said lead author Maryam Oskoui, MD, MSc, pediatric neurologist at The Montreal Children’s Hospital (MCH) of the MUHC, co-director of the Canadian Cerebral Palsy Registry, and assistant professor in the Department of Paediatrics and Department of Neurology and Neurosurgery at McGill University. “How these genetic factors interplay with other established risk factors remains to be fully understood. For example, two newborns exposed to the same environmental stressors will often have very different outcomes. Our research suggests that our genes impart resilience, or conversely a susceptibility to injury.”

This finding, published in a study online in Nature Communications, could have major implications on the future of counselling, prevention, and treatment of children with CP, the authors suggested.

“When I showed the results to our clinical geneticists, initially they were floored,” said principal investigator Stephen Scherer, PhD, DSc, director of The Centre for Applied Genomics (TCAG) at The Hospital for Sick Children. “In light of the findings, we suggest that genomic analyses be integrated into the standard of practice for diagnostic assessment of cerebral palsy.”