AUTISM IS NOT A SPECTRUM, IT’S A TYPE
New Princeton research reveals 4 distinct subtypes of autism.
Each has different causes, brain patterns, and traits.
Using machine learning on data from 5,000+ autistic children (ages 4–18), researchers identified four robust subtypes, each with its own patterns of traits, genetics, and developmental timing.
1. Social & Behavioural Challenges (~37%)
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Classic autism traits (social communication difficulties, repetitive behaviours).
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Developmental milestones (walking/talking) usually on time.
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High rates of co-occurring ADHD, anxiety, OCD, depression.
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Stronger link to common genetic variants (e.g., ADHD/depression) and genes active after birth.
2. Mixed ASD with Developmental Delay (~19%)
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Delayed developmental milestones (motor and speech), but generally fewer psychiatric issues.
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Mainly linked to rare inherited mutations, often present from birth.
3. Moderate Challenges (~34%)
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Milder autism traits overall.
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Milestones reached on time.
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Few co-occurring conditions; lower support needs.
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Genetic profile shows modest rare variant burden in less critical genes.
4. Broadly Affected (~10%)
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Severe across multiple domains: delayed milestones, communication, social skills, mood disorders.
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Highest burden of de novo mutations (new mutations not inherited) in developmental genes.
What This Means
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These subtypes have distinct underlying biology and genetic signatures, not just behavioral differences.
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The timing of gene-expression effects may vary: some mutations act prenatally, others later in childhood, aligning with clinical features.
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This reframes autism as multiple “autisms”, rather than a single continuum. It helps explain why past genetic studies struggled: they combined heterogeneous cases that were actually biologically distinct.
Researchers aim to:
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Expand to adult populations, females (who are often underrepresented), and cross-cultural samples
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Develop biomarkers or screening tools that classify autism subtypes automatically
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Explore if subtype-specific treatments (pharmacological or behavioral) have better outcomes
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Study how gene expression timing maps to neurodevelopmental windows
Autism may not be “one thing” with different severities but many things with different causes.