The heritability of autism refers to the extent to which the disorder is influenced by genetic factors. While there is no single synonymous phrase for this concept, there are several related terms that are often used interchangeably. These include genetic susceptibility, familial clustering, and genetic predisposition. Other related concepts include penetrance, expressivity, and allelic heterogeneity, which describe variations in the expression and severity of autism spectrum disorders across individuals with the same genetic makeup. Understanding the heritability of autism is important for developing effective interventions and treatment strategies for individuals affected by the disorder and their families.