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RESEARCH Genes and Cerebral Palsy Understanding the science of genetics and what it could mean for families By AMY HOGAN and THE LIGGINS INSTITUTE For many years, the cause of Cerebral Palsy (CP) – Hōkai Nukurangi has been explained as being an early brain injury, occurring before, at or after birth. Events causing CP can include premature birth, infections or other maternal illnesses during pregnancy, or a lack of oxygen around the time of birth. However, for many children, the cause remains unclear. New research shows another factor can be part of the story: genes. This doesn’t mean that CP is now “genetic only”. CP often has multiple contributing factors. Fact and fiction Fact: 14-30% of people with CP may have a genetic change that contributed to their condition. The wide range exists because studies use different methods and include different groups of people. Over time, these estimates are likely to become more precise. Fiction: There’s a single “CP gene”. Scientists have identified hundreds of genes where variants may increase the risk of CP. Each genetic change is usually rare and can affect different biological pathways. Fact: Many genetic changes in CP happen spontaneously. Parents didn’t “cause” these changes and couldn’t have prevented CP in their child. Fiction: If CP has a genetic cause, it’s no longer CP. The diagnosis is based on symptoms, not the cause. Fact: Premature birth, infections, or other complications are still important – and sometimes these factors work together with genetic vulnerabilities. The science of genes and CP Key findings so far: • More than 300 genes have been reported in CP • Over 160 are considered strongly linked to CP based on current evidence • Most variants are rare, and many genetic changes are unique to a person or family • DNA changes can matter: Some people with CP have small sections of DNA that are missing or duplicated. These are called copy number variants (CNVs) and can affect brain development. • There can be overlaps: Some genes linked to CP are associated with epilepsy and other conditions. It’s important to note that while intervention is the key goal of genetic studies, cases of direct symptom alleviation are still relatively rare, and the focus is on building information in these early stages. Genetic testing – how it works • Sample: Usually, a blood or saliva sample from the person with CP, and sometimes their parents. • Analysis: DNA is examined for rare changes – either 16 | THE REVIEW MARCH 2026