Autism and asthma are two common but seemingly unrelated conditions. Autism is a chronic neurodevelopmental condition, characterised by difficulties in social communication as well as repetitive behaviours/restricted interests. On the contrary, asthma is a chronic respiratory condition characterised by periods of wheezing, shortness of breath and chess tightness. Despite the distinct features, there is some evidence suggesting an increased prevalence of asthma in individuals with autism, while maternal history of asthma has been associated with autism in the offspring. The reasons underlying these observational associations are currently unknown. One possible explanation could be that there is a shared genetic aetiology between the two conditions. Testing this hypothesis will be an important first step towards understanding the reasons of their co-occurrence.