Autism and Genetics: What Can Genetic Testing Actually Tell You?

Autism & Genetics is an important area of research because genetic factors can contribute to autism. Studies have identified some genetic changes would be associated with autism, but there is no single “autism gene” that explains every case.[1,2]

Some genetic changes can be inherited from a parent, while others, called de novo mutations, arise in a child and are not found in either parent. Genetic factors can also interact with other biological, metabolic, and developmental influences.[1]

This means that asking “is autism genetic?” does not have a simple yes or no answer. Genetics can contribute to autism, but they do not determine every child's outcome.

What Can Genetic Testing Reveal?

Genetic testing for autism does not diagnose autism itself. Instead, testing may identify a genetic condition or genetic change that is associated with developmental differences, intellectual disability, seizures, or other clinical features.[2,3]

Depending on the child's history, a healthcare professional like geneticist or child developmental paediatrician may consider different types of genetic testing. Testing can examine chromosome changes, specific genetic conditions, or any changes across many genes.

Results may help explain some developmental concerns, guide medical monitoring, inform family planning discussions, and connect families with genetic counseling.[3]

A negative result does not mean that genetics play no role. Current testing cannot identify every genetic factor associated with autism.[2]

The American Academy of Pediatrics guidance on autism discusses the role of genetic evaluation within comprehensive autism care.

What About Family History and Inherited Changes?

Having a family history of autism can increase the likelihood that genetic factors contribute to a child's development. At the same time, autism can occur without a known family history.[1]

Genetic testing can therefore provide useful information in some families, but it should be interpreted by a qualified healthcare professional. Consumer genetic reports, including direct-to-consumer tests, should not be treated as a diagnostic assessment for autism.

The National Human Genome Research Institute's information on genetic testing explains what genetic tests can reveal and why professional interpretation matters.

Book a genetic consultation to discuss whether genetic testing may be appropriate for your child or family.

Frequently Asked Questions

Is autism genetic?

Genetic factors can contribute to autism, but autism does not result from one single gene. Many genetic and developmental factors can contribute.[1]

Can genetic testing diagnose autism?

No. Genetic testing may identify genetic conditions or changes associated with autism, but it does not independently diagnose autism.[2,3]

What genes are linked to autism?

Many genes have been associated with autism. Researchers continue to identify and study genetic changes that may influence neurodevelopment.[1]

What are de novo mutations in autism?

De novo mutations are genetic changes that arise in a child and are not inherited from either parent. Some have been associated with neurodevelopmental conditions, including autism.[1]

What is the role of whole exome sequencing in autism?

Whole exome sequencing examines many protein-coding regions across the genome. It may help identify genetic changes when a child has developmental differences or other clinical features that warrant testing.[3]

Should autistic children have genetic testing?

Genetic testing may be appropriate for some autistic children, particularly when there are additional developmental, neurological, or physical findings. A qualified healthcare professional can help determine whether testing is suitable.[2,3]

Can a blood test diagnose autism?

No. A blood sample can be used for certain genetic investigations, but there is no single blood test that independently diagnoses autism.[2]

References

• Large-scale exome sequencing study implicates both developmental and functional changes in the neurobiology of autism. Cell. 2020,
• Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. 2020.
• Exome and genome sequencing for pediatric patients with congenital anomalies or intellectual disability: an evidence-based clinical guideline of the American College of Medical Genetics and Genomics. Genet Med. 2021.
• Lord C, Brugha TS, Charman T, Cusack J, Dumas G, Frazier T, et al. Autism spectrum disorder. Nat Rev Dis Primers. 2020.
• National Human Genome Research Institute. Genetic Testing. Bethesda (MD): National Institutes of Health.