Is Autism the Consequence of Genetic Dysfunctions?

Autism is a complex neurological disorder that involves abnormalities at the level of the central nervous system. Although the specific causes of autism in remain unknown, it seems that acquired or inherited genetic dysfunctions have a very important role in the occurrence of the syndrome in people. Recent experiments conducted on mice have proved that there is a clear connection between genetic factors and abnormal behaviors characteristic to ASD (autism spectrum disorders). By deleting the PTEN gene in some areas of the brain of mice, scientists have been able to trigger symptoms that are very similar to those generated by autism in humans.

Although the experiment can't explain the exact phenomenon that leads to the development of autism in people, the results suggest that autistic people present abnormalities in a region of the brain called hippocampus. When researchers deleted the PTEN gene in the hippocampus of mice, the results were remarkable. The mice with the PTEN gene deleted quickly began to follow the behavioral patterns generated by autism in humans. The abnormal mice showed clear signs of impairment at the levels of social interactions, rapidly losing their interest in other mice. The mice with the PTEN gene deleted suffered a pronounced decrease of their sensorial perceptions and quickly showed signs of poor adaptation to unknown environments and new situations.

From a physiological point of view, the abnormal mice had very thick nerve cells and presented dysfunctions of myelin, the substance that surrounds the body's neurons, enabling the transmission of nervous impulses. These anatomical abnormalities characteristic to the mice with the PTEN gene deleted are a huge step forward in understanding the occurrence of autism in humans. Nevertheless, now that medical scientists have been able to simulate the symptoms of autism in mice, new medical treatments can be tested in an attempt to reverse the neurological damage caused by the disorder.

The medical scientists who conducted the experiment were able to reveal many similarities between the behaviors of mice with the PTEN gene deleted and the behaviors of people with autism. The abnormal mice involved in the experiment showed a lot more interest in various objects rather than in other mice. They also became passive, and withdrawn, avoiding any form of interaction with other mice. They began to show signs of poor adaptability, failing to integrate into new environments. Also, the mice with the deleted gene became stressed when confronted with new situations, unlike normal mice, which didn't experience difficulties in adapting to unknown scenarios. The major difference, however, was that unlike autistic people, the abnormal mice didn't show any signs of repetitive behaviors or insistence on sameness.

The overall results of the experiment reveal a strong connection between the PTEN gene and abnormal behavioral patterns. However, medical scientists aren't yet able to tell if dysfunctions of this particular gene are also responsible for causing autism in humans.