Autism and attention deficit hyperactivity disorder (ADHD) are not one and the same. But research into the similarities as well as the differences between the two conditions has been getting somewhere in recent years.
Autism and ADHD are both spectrum disorders. In part, what this means is that there are a wide variety of types and severity of symptoms for both conditions.
In the cases of both autism and ADHD, parents usually will have a sense that something is out of the ordinary with their young child.
Children with autism and children with ADHD may have a tendency to lose their tempers or to cause disruptions in other ways. It's not uncommon for children with autism and children with ADHD to not seek out, or to avoid, eye contact.
They may not seem to hear what is said to them. They may act impulsively, without thinking. Fine motor skills and gross motor skills may be lacking in one of a number of ways.
As published in the October, 2002 issue of American Journal of Human Genetics, a study has found both autism and ADHD to be connected with chromosome 16. It is thought that this one gene may predispose the individual to be vulnerable to a range of different conditions. Researchers also believe that other factors like environmental influences may be in play.
A study from the University of Chicago Medical Center, the University of Illinois at Chicago and the Roswell Park Center Institute has found an association between autism and the absence of a piece of chromosome 16 which is called 16p11.2. This research was published online on December 21, 2001 in the journal Human Molecular Genetics.
This loss of part of a chromosome is called a microdeletion. Microdeletion of 16p11.2 is the second most common genomic disorder that has been found to have a relationship to autism. Its absence takes approximately 25 genes out of the picture.
Some of these genes are involved in cell interaction and others affect the brain and behavior. The researchers suggest that other of these missing genes may be part of the cause of cognitive, language and social disabilities.