Imagine your child, previously happy and healthy, suddenly starts refusing to use his growing vocabulary shortly after his second birthday. He instead begins to motion for food and toys and becomes unsettled when you try to get him to speak. You decide he’s going through a shy period and think nothing of it. A few weeks later, the daycare asks you to wait for a few minutes after picking him up from school. It seems that he’s not interacting with the other children and prefers to spend most of his time alone with one particular stuffed bear, which he now has clutched in his hands. When you try to take it away, he becomes very agitated and begins to mumble the same sound over and over again.
Like one out of every 150 children, your child may be developing some form of autism.
Autism can vary in severity and may express with some or all of a host of symptoms that appear between the ages of 2 and 3. Commonly shared symptoms include:
Adapted from: Google Health
It has long been thought that autism and Autism Spectrum Disorders (ASDs) have some genetic components. It is much more likely that identical twins will both have some form of ASD than fraternal twins. However, because expression of ASDs varies so much between individuals, it is thought that multiple genes—as well as environmental elements—are involved with the ASD phenotype. In the past, studies have been done which linked certain SNPs to 1% of ASD cases and have located several chromosomal regions where an ASD-associated gene might be found, but this is the first case of such in-depth study on the subject (Wang et. al, 2009).
Recently, a gene has been discovered which could account for 12-18% of autistic cases. 3,100 people from 780 families took part in the survey, which discovered the “autistic gene”. It was discovered that people who had gene variants in and around the CDH10 gene had a higher chance of having autism. While the gene variant exists in unaffected individuals, it is 20 times as likely to appear in a person affected by an ASD (Wang et. al, 2009).
This web page was produced as an assignment for an undergraduate course at Davidson College.