Autism: The environment is more important than genes

'In terms of the cause of autism, environmental factors can play a more important role than previously thought' is the conclusion drawn from genetic research in the United States.

A Stanford research team compared cases of autism in 54 twins with eggs and 138 other egg twins that share half of the same genes. In each pair, there is at least 1 child with autism.

They found that the same twins have a higher risk of autism than other egg twins. But other pairs of eggs have a higher risk of developing autism than children in families with siblings who have autism.

Accordingly, the common environment in twins explains about 55% of autism cases, of course, genetic factors still play an important role.

' Environmental factors play a more important role than previously thought, ' said Dr. Joachim Hallmayer, Stanford Medical University (California, USA), who led the study.

In another study by the research lab of Kaiser Permanente insurance company (Oakland, California, USA), Lisa Croen, research leader and director of the Autism Research Program, said: mothers who have children themselves Century tends to take antidepressants for 1 year before they are twice as pregnant as mothers with healthy babies after examining mothers' medical records of 300 autistic children and 1,500 children. randomly selected. And the risk is even greater (3 times higher) when the drug is taken during the first 3 months of pregnancy.

The findings published in the journal Archives of General Psychiatry suggest that some elements of pregnancy, such as drugs, chemicals or infections, can trigger autism in children who already carry disease genes. .

' There are genetic factors that may contribute to an increased risk of autism. We have clear evidence that the leading cause of disease is hereditary and prenatal environmental factors can play an important role in the development of autism ', Clara Lajonchere, author The author of the study and the program president said Autism said.

Autism is a collection of disorders, from inability to communicate to mental retardation or mild symptoms with Asperger's syndrome. It affects 1 in 150 babies born in the US or in other words accounts for 1% of the population.