Lack of oxygen at birth has always been considered the main factor, but new research suggests genetics play a larger role.
The world’s largest study of cerebral palsy genetics has determined that genetic defects are responsible for about a quarter of cases in Chinese children.
The collaboration between the University of Adelaide and Fudan University in China included nearly 1600 children with an average age of 24.5 months and clinical manifestations of cerebral palsy.
Of these children, 387 got a genetic diagnosis (24.5%).
Cerebral palsy has diverse risk factors, causes and symptoms and the neurobiological pathways involved are not yet understood. Using gene burden analysis, researchers were able to identify 25 genes linked to cerebral palsy.
These included 19 which were already established as neurodevelopmental disease genes, meaning six are potential new areas for cerebral palsy research.
The authors explained that early diagnosis can be difficult as clinical manifestations develop gradually and become more prominent with age. Therefore they believe exome sequencing should be considered as a first-line diagnostic test.
“We discovered that a sizeable fraction (8.5%) of these genetically diagnosed cases with clinical manifestations of CP have clinically actionable findings,” they wrote.
They believe that this proportion of children could have benefited from early intervention options, such as genomic-informed medication or diet changes, had the disease been detected earlier using genetic testing.
The researchers strongly recommend performing genetic testing of children diagnosed with cerebral palsy, preferably within their first one to two years of life, to identify those who might benefit from early and customised interventions.
“Targeting the underlying cause can improve their neurological outcomes. Early detection and timely intervention are of utmost importance for reducing the incidence of neurological disabilities in populations with CP,” they wrote.
Using exome sequencing, the study also determined the genetic diagnostic rate of the cohort in relation to perinatal asphyxia. Contrary to the previously held belief that oxygen deprivation at birth is the main cause of cerebral palsy, this study found that perinatal asphyxia may be secondary to the underlying genetic aetiology.
Thirty percent of those genetically diagnosed with cerebral palsy also had documented perinatal asphyxia, which is 1.3 times higher than the number of children genetically diagnosed who did not experience documented perinatal asphyxia (22.8%).
“This implies that, in approximately one-third of CP cases attributed to asphyxia, the CP presentation is likely to be a direct or a secondary outcome of the inborn genetic defect and possibly misattributed to asphyxia as the etiological driver of CP,” they wrote.
