We do not routinely see patients with autism in the Genetics service, unless there are additional features, or a significant family history. There is no genetic test to diagnose autism.
The genetics of autism remains poorly understood, and it is hypothesised that autism results from a complex interaction of polygenic and environmental factors. It is not unusual to see several individuals with autism in one family. Studies have suggested that parents who have one child affected with autism, are more likely to have another affected with autism (~18% recurrence risk). The recurrence risk is higher if there are multiple affected siblings, and for male offspring.
If you feel that the patient has additional features to suggest an underlying syndromic diagnosis, please feel free to refer, or to get in touch to discuss.