Thursday, August 3, 2023

Autism Spectrum Disorder and the Genetic Contributions

     Autism is usually discovered in early childhood by communication dysfunctions and social interactions as well as repetitive and restrictive behaviors and interests.  Autism spectrum disorder is a heterogeneous group of neurodevelopmental conditions set by specific criteria. The main areas affected by this disorder are language level, intellectual functioning, and co-occurring psychiatric and medical difficulties, all of these ranging from very severe to moderate.  The male-to-female ratio of autism is 4:1 in a clinical study.  This sex difference is unknown why but there are a few ideas that were thrown around, one being that there are more underdiagnoses and misdiagnoses in women.  70% of people with autism have other conditions alongside it, the main ones being ADHD, anxiety, depression, epilepsy, sleep problems, and gastrointestinal and immune conditions.  The twin studies suggest that 9-36% of the variance in autism could be from environmental factors, not genetic ones.  From pregnancy-related nutrition factors to heavy-metal exposure, there is a wide range of factors that could be associated with autism outside of the genetic conclusion.  Looking into the genetic world of autism, there are findings from linkage, candidate gene studies, common and rare genetic variation studies, epigenomics, and transcriptomics.  Linkage studies can show the regions of a chromosome that are inherited in affected individuals.  Another example is the SNP-heritability of autism which ranges from 65-12%, showing that variation of a single nucleotide could play a big part in this inheritance.  Looking through this paper there is so much information on different studies down to help prove these theories. There are so many different factors that can contribute to autism and many methods discovered to help investigate the genetic variants that carry out autism and autistic traits.

    The first image, a, explains variance by different classes of variants in autism.  The shades of green show familial recurrence and the purple being the environmental factors that could contribute.  Image b is showing showing the variance change in phenotypic subgroups.  ,measured%20genetic%20variants%20influence%20phenotypes.


  1. This was very interesting to read. I have always wondered if what a women eats while pregnant can have any type of affect on a child that ends up being born with autism. It was also interesting to read that people with autism can possibly have other conditions such as ADHD, anxiety, depression, and epilepsy.

  2. This was really interesting because I didn't know that if you have autism you are also likely to have other conditions as well. It is also interesting that environmental factors could also play a role in this.