Genetic testing, explained without the jargon
Testing cannot diagnose autism — your child already has that answer. What it can do is find an underlying condition that carries its own health risks, its own screening plan, and occasionally its own treatment.
The short answer
- Testing finds an explanation in roughly 1 in 6 children overall: closer to 1 in 3 with other medical features, nearer 1 in 12 for autism alone.
- Exome or genome sequencing is now recommended as a first-choice test where there is developmental delay or intellectual disability.
- We do not support or promote prenatal or embryo screening for autism.
- Deciding not to test is legitimate. Autistic people have rights over their own genetic information.
If your child is under 5
Ages 0–4- Yield is highest when there are other medical features — growth, seizures, heart or kidney findings.
- Results may change screening schedules early, which is the main practical benefit at this age.
- Action: ask what a positive result would change this year — screening plans matter more than a label.
Changes when you change the age at the top of the page.
If your child is 5 to 8
Ages 5–8- School teams sometimes ask whether genetics has been offered; a clear yes, no, or not yet is enough.
- If a condition with medical screening is found, put the schedule in writing for the pediatrician.
- Action: decide with your clinician whether sequencing is useful now; document medical necessity if authorization is needed.
Changes when you change the age at the top of the page.
If your child is 9 to 12
Ages 9–12- Your child may notice blood draws and want a plain explanation of what the test can and cannot answer.
- Results rarely change day-to-day classroom strategies, but they can change medical follow-up.
- Action: prepare a short explanation beforehand; ask who will help interpret uncertain results.
Changes when you change the age at the top of the page.
If your child is a teenager
Ages 13–16- Your child's own view matters here, and increasingly carries legal weight.
- Autistic people have the right to decide about their own genetic information — including deciding not to know.
- Action: involve your teenager in consent and in whether secondary findings are reported.
Changes when you change the age at the top of the page.
Pooled yield across sequencing studies. Every figure here names its study in the sources below.
What a result can change
A named condition sometimes comes with a screening schedule — hearts, kidneys, eyes — and occasionally with a specific treatment. That is the practical case for testing.
It never comes with a ceiling. Genetic diagnoses give population-level information, not individual destinies.
What it will not do
- Diagnose autism
- Find something in every child
- Change who your child is
- Replace educational evaluation or supports
Autism is diagnosed clinically — getting assessed. Codes on reports: diagnostic codes.
Who is often offered testing
Yield is higher when there is developmental delay, intellectual disability, epilepsy, congenital anomalies, or other medical features. Autism alone can still be an indication in many practices — discuss with genetics or your developmental clinician.
Deciding not to test
Some families read everything here and decide not to test. That is a legitimate decision. Autistic people have the right to decide about their own genetic information as they gain capacity.
After a result
- Ask for plain-language summary
- Who follows which screening?
- What is uncertain vs established?
- How do we tell family members if relevant?
- How do we talk with the child as they grow?
Related
Seizures · Why autism happens · Diagnostic codes Some families read everything here and decide not to test. That is a legitimate decision, and autistic people have the right to decide about their own genetic information.
Questions to ask genetics
- What are we looking for, and how often do you find something in a child like mine?
- What happens if the result is uncertain?
- Who follows medical screening if a condition is found?
- How should we talk about this with our child as they grow?
- What would you do if this were your family?
Write the answers in your notebook. Future clinics will ask the same things.
Practical prep for the blood or saliva draw
- Ask for the first or last appointment of the day
- Pack headphones, a preferred video, and a snack for after
- Request numbing cream if appropriate
- Tell staff the child’s communication method in advance
See medical appointments for a fuller accommodation list.
Parent trap to avoid
Do not delay needed medical screening for a named genetic condition while waiting for perfect certainty. Uncertain genetic results and clear medical follow-up can both be true.
Questions parents ask after reading this
Use these with your co-parent, teacher, or clinician so the next conversation is concrete.
- What is the single highest-yield change we can make in the next seven days based on this page?
- What should we stop doing that is adding load without helping?
- Who else needs a one-page summary of this plan (school, caregiver, relative)?
- What would “a little better” look like in two weeks so we know the plan is working?
Write the answers down. Plans that live only in your head disappear on hard days.
If you only do three things
- Pick one action from this article and schedule it on the calendar (call, email, or routine change).
- Tell one other adult the plan in one sentence so you are not carrying it alone.
- Revisit this page after two weeks and note what changed — keep, adjust, or drop.
Small completed steps beat perfect unread plans. You are allowed to go slowly and still be a good parent.
Questions parents ask
Where this comes from
- Pooled diagnostic yield across exome and genome sequencing studies, 2020–2026.
- June 2026 joint statement of three professional organisations on sequencing after developmental diagnosis.
This is health information, not medical advice. It cannot replace a conversation with your child's doctor.