Autism is genetic, and why this matters more than ever right now

I have believed for a long time that autism is genetic. It is something I have seen in families across my clinical career - the parent who comes in with their child and quietly says "I think I might be autistic too." The sibling who presents with the same profile. The patterns that repeat across generations in ways that are impossible to ignore once you start looking for them.

So when the National Autistic Society published its definitive statement earlier this month, and in turn stated for the first time, after reviewing 83 research papers, that autism is genetic - I really felt something close to relief. Not because it was news to me, but because it now has the weight of a formal, evidence-based position from one of the most respected autism charities in the world.

The review is clear on the key points. You are born autistic and you are autistic for life. Most autistic people are autistic because of genes they inherited from their parents, which is why autism often runs in families. There is no single autism gene, thousands of genes combine, and scientists believe there are many more still to identify. There is no genetic test for autism, and genetic testing cannot predict or diagnose it.

What I find equally important is why the NAS felt compelled to state this now. This work is important in light of the daily challenge of false claims about autism in the media and politics in the UK and the US, which are spreading harmful lies and distracting from the very real issues autistic people face. That context matters. When misinformation fills a vacuum, it causes real harm — to families, to individuals seeking diagnosis, and to the clinical professionals trying to do right by them.

For those of us working in assessment and training, this statement has practical implications. It reinforces what gold-standard diagnostic practice already reflects — that a thorough developmental history, a careful family history, and an understanding of how traits manifest across generations are not optional extras. They are central to getting the diagnosis right.

There is also something important in what autistic people themselves said when the NAS shared the review with them. The majority felt the information would help dispel myths, but many expressed concern it could lead to parental guilt or blame. That tension is one every clinician in this field will recognise. How we communicate genetic information — with care, with context, and without inadvertently adding to a family's burden — is a clinical skill in itself.

This is exactly the kind of development I think every clinician working in neurodevelopmental assessment should read and think about. You can find the full review, and the NAS blog on why this matters right now, at autism.org.uk.