Objective To investigate the relationship between the Apolipoprotein E (APO E) ϵ4 allele and severity of functional motor impairment in cerebral palsy (CP).
Methods Cross-sectional study of 153 individuals with CP. Mean age was 9.1 years; 54% were males. 61% were preterm at birth; 35% less than 30 weeks gestation. Genomic DNA was extracted from buccal swabs for APO E genotyping. Functional motor severity was assessed by the Gross Motor Function Classification System (GMFCS), on a scale of 1–5, grouped as levels 1–2 (low severity) and 3–5 (high severity). Chi-square and logistic regression techniques were used to assess the association between the APO E ϵ4 allele and CP severity and to adjust for other risk factors, such as timing of brain injury, gestational age, and type of CP.
Results 31% of subjects had at least one ϵ4 allele. There was a trend towards significance for subjects with at least one ϵ4 allele assigned to the low severity group (p = 0.11). ϵ4 was significantly associated with low severity when adjusted for the effect of timing of injury. Infants with brain injury in the perinatal period were 4.3 times more likely to be in the low severity group (p = 0.01).
Conclusions The APO E ϵ4 allele appears to confer protection and/or facilitate recovery after brain injury in the fetus or newborn, particularly when that injury occurs around term. This finding has important implications for future therapeutic trials that mimic the beneficial effects of APO E.