Autism spectrum disorder and macrocephaly: a systematic review and meta-analysis

Trabalho final do 6º ano médico com vista à atribuição do grau de mestre (área científica de pediatria), apresentado à Faculdade de Medicina da Universidade de Coimbra.Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder. Macrocephaly frequency in ASD is higher than in typically developing peers and one of the most consistent findings. We performed a systematic review and meta-analysis of studies measuring head circumference in ASD children samples. We identified 196 studies through searching strategy and selected 28 studies to include in the meta-analyses. We performed a meta-analysis from a total of 828 children (out of 5185 with ASD) founded with macrocephaly in those 28 studies. The percentage of macrocephaly in the ASD children sample was significantly higher than the expected to general population (95% confidence interval found for ASD children was [14.7, 21.2] versus 3%, respectively). This result supports macrocephaly as a potential biomarker of ASD with implications in future clinical research