Difference between revisions of "Causes"

Revision as of 15:45, 23 March 2010

Causes

Scientists have not found the exact cause of ASD, although all would agree that there is a genetic basis. Strong genetic factors have been found for some of these disorders such as in Rett Syndrome, and there are simple tests for diagnostic purposes for these disorders.

The difficulty in finding the cause of ASD partially lies in its definition, and partially on the complex interplay between genes that happens during development. ASD, like most other behavioral disorders, is diagnosed based off of observable characteristics of the child. However, these diagnosis offer no direction as to which specific genes are defective. Furthermore, two patients with ASD can present very similar symptoms and yet have different defective genes or causes. For example, Rett Syndrome is caused by mutations in the gene MeCP2 while Tuberous Sclerosis is caused by mutations in TSC1 and TSC2. It should be noted that both Rett Syndrome and Tuberous Sclerosis are very rare. It may be that there are certain genes which are more susceptible to environmental influences. If these environmental triggers are there, then the child will develop specific ASD phenotypes, such as a poor language development.⁹

There are many theories for the cause of ASD. Some include the

1. Theory of Mind
2. Simulation of Systems
3. Weak Coherence
4. Fetal Testosterone Hypothesis
5. Oxytocin and AVP
6. Abnormal Cellular/Synaptic Growth Hypothesis
7. Stimulating Hypothesis
8. Abnormal Cellular/Synaptic Growth Hypothesis