What role does inheritance play in autism?

The inheritance of autism is highly complex. Genetics appears to play a large role in the development of autism spectrum disorder. Studies involving twins determined that up to 90% of the differences between autistic and non-autistic people are due to genetic effects. It is still unclear whether interactions of multiple genes are involved or rare changes to single genes have major effects. A recent study in 2008 did identify a change in a specific protein that increased the risk of developing autism. Further studies are needed to determine the causes in more detail.
Genetics is a clear part of autism, but not all of the genetic risk is inherited. Some of the genetic changes that lead to autism are de novo, which means mutations in the egg or sperm.
William Stillman
Health Education

Genetic predisposition is one of several prominent theories under consideration (and research) for what causes autism. It is not uncommon for one or more parents (often the birth father) to have autistic traits or to be self- or formally-diagnosed with Asperger's Syndrome. This would seem to lend credence to the thought that heredity or inheritance affects the likelihood of autism.

If this is a question you're wondering, it may aid you to consider autism in this manner so as to put your relationship with your child's other parent in perspective. Has he always been "quirky" or considered a loner? Was he a "computer geek" or a "book worm"? Does he struggle socially or appear to "act" in order to "pass" socially? Does he have a very different logic, or is he fluently verbose on very select topics (but flounders otherwise)?

What about other relatives and family members? Anyone called a hermit or recluse? Or remembered as seeming to be cold or aloof? Mulling these questions may be points to consider in making sense for whether the genetic theory of autism best applies to your family (and perhaps your relationship with your child's other parent). 

Riverside Health System

Twin and family studies strongly suggest that some people have a genetic predisposition to autism. Identical twin studies show that if one twin is affected, there is a 90 percent chance for the other twin to be affected too. Several studies are in progress to determine the specific genetic factors associated with the development of autism spectrum disorder (ASD). In families with one child with ASD, the risk of having a second child with the disorder is approximately five percent, or one in twenty. This is greater than the risk for the general population. Researchers are looking for clues about the genes that contribute to this increased susceptibility. In some cases, parents and other relatives of a child with ASD show mild impairments in social and communicative skills or engage in repetitive behaviors. Evidence also suggests that some emotional disorders, such as manic depression, occur more frequently than average in the families of people with ASD.

This answer is based on source information from the National Institute of Neurological Disorders and Stroke.

Continue Learning about Autism Spectrum Disorders (ASD) Causes

Autism Spectrum Disorders (ASD) Causes

Autism Spectrum Disorders (ASD) Causes

The causes of autism spectrum disorders (ASD) have been hotly debated. While scientists suspect that both genetics and environment play a role, there is no certainty about what's behind this group of neurological disorders. Resear...

ch continues, searching for the causes. Find answers to your questions about autism spectrum disorder and autism risk factors with expert advice from Sharecare.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.