Scientists Identify 2 Distinct Subtypes of Autism in The Brain

An international team of researchers has discovered two distinct subtypes of autism based on brain connectivity patterns in both mice and humans. The study analyzed brain scans from 940 children and young adults with autism, 1,036 neurotypical individuals, and mice with 20 models of autism-like brain traits, revealing two primary groups: one with reduced connectivity (hypoconnectivity) linked to synaptic genes, and another with increased connectivity (hyperconnectivity) tied to immune system genes. The hyperconnectivity group showed slightly more severe autism symptoms. The findings were validated across species and datasets, suggesting these subtypes reflect genuine biological differences. However, about one in four autism cases did not fit into either category, indicating potential additional subtypes. Researchers used mouse models as a 'Rosetta Stone' to decode pathways driving human brain patterns, translating genetic and immune factors into observable connectivity signatures. Neuroscientist Alessandro Gozzi from the Italian Institute of Technology emphasized the breakthrough, stating that decades of observed variability in autism now have direct biological evidence. The study builds on prior research, such as a 2025 study identifying four autism subtypes based on behavioral traits, but this approach focuses on brain imaging and genetic links. If confirmed, these subtypes could enable tailored therapies, moving away from a 'one-size-fits-all' approach. The team plans further work to refine diagnostics and develop targeted interventions, though challenges remain in classifying the remaining quarter of cases. The research highlights the complexity of autism and the potential for precision medicine to address its diverse manifestations.