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Having autism in the family often raises questions about genetic risk. If your brother or sister has autism, you might wonder how this affects the chances for your own future children. Autism Spectrum Disorder (ASD) does have a genetic component, and family history can play a role. This post breaks down what science says about family autism risk and how new genetic testing tools can help, so you can plan with confidence.

The Genetic Connection: Why Autism Can Run in Families

Research shows that having a family member on the spectrum can increase the likelihood of autism in the next generation. Autism is considered highly heritable – studies estimate that roughly 50–80% of the risk comes from genetic factors. However, it isn’t entirely genetic. Only about 20–30% of autism cases are monogenic, meaning tied to a specific gene mutation or identifiable cause, while the rest are multifactorial – caused by a complex mix of many genes and environmental factors (My brother has autism, what does this mean for me?). There is not one single cause, or an “autism gene” - that’s why one sibling can have ASD while another does not.

Sibling with Autism: Impact on Your Future Child’s Risk

So, what does it mean if you have a sibling with autism? Your future child’s odds of ASD will be higher than someone with no family history – but just how high is dependent on many factors. The risk of recurrence for multifactorial autism is heavily influenced by the severity of autism in the family as well as the number and biological sex of the people affected. Critically, if your sibling’s autism is due to a known genetic cause (like Fragile X syndrome), that information gives a clear target for testing and helps predict the odds of passing it on.

Whole-Genome Preimplantation Genetic Testing: Planning Ahead

Whole-genome preimplantation genetic testing (PGT) allows the DNA of IVF-created embryos  to be screened for a subset of known genetic causes of autism before pregnancy (Genetic Testing for Autism, Intellectual Disability, and other Neurodevelopmental Disorders). Orchid’s embryo screening, for example, scans embryos for hundreds of genes known to cause genetic forms of autism and other neurodevelopmental disorders. If a particular autism-related mutation is known to run in your family, targeted embryo screening through PGT-M can identify which embryos inherited it – letting you choose an embryo without that mutation. For those without a known single gene cause for the autism in their family, risks will remain elevated, but , this testing may still catch certain genetic variants associated with autism that occur by chance (de novo). While no test can guarantee a child won’t have autism, these tools can reduce the likelihood by helping you avoid known risk factors.

Conclusion

Having a sibling with autism doesn’t guarantee your future children will too – understanding your family’s genetic risk may allow for additional screening before pregnancy. By using modern tools like whole-genome PGT and getting guidance from genetic counselors, you can make informed decisions for a healthy family future. Ultimately, knowledge is power – understanding your family risk today gives you confidence and peace of mind for tomorrow.

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