Figure 1. Inheritance patterns of autism spectrum disorder.

Adapted from: Bourgeron T. From the genetic marachitere to synaptic plasticity in autism spectrum disorder. Nat Rev Neurosci. 2015;16(9):551-63. Review.

Low and high-risk variants can contribute to ASD etiology. A variant harboring a high risk is enough to cause the disease alone. In such situation, usually the variant has risen as a de novo mutation, and parents do not harbor risk variants, characterizing a monogenic attern of inheritance. In a second situation, characterizing an oligogenic pattern of inheritance, parents can harbor moderate-risk variants that can be inherited by the child, leading to the disease. A polygenic or multifactorial patter of inheritance would be the cases of inheritance of a moderate load of low-risk variants plus a moderate-risk variant, or a high load of low-risk variants.