Why Are Boys More Prone To Autism? It's In The Genes
Autism is much more prevalent in boys than in girls, and researchers now think they know why, according to a new study, published in the journal Human Molecular Genetics. Five rare gene mutations appear to increase the chances that a boy will develop autism, researchers said.
Researchers found that mutations on the AFF2 gene, which resides on the X chromosome, increase the risk for autism. While both boys and girls have an X chromosome, girls have a second copy which can compensate for a faulty gene, while men only have one.
Like Us on Facebook
"Our data suggest that AFF2 could be one of the major X-linked risk factors for [autism spectrum disorders]," Michael Zwick, study author and assistant professor of human genetics at Emory University School of Medicine, said in a statement.
Researchers looked at data from 202 boys diagnosed with autism and found that mutations in the AFF2 gene were five times more abundant in boys diagnosed with autism, compared to normal boys.
The findings give credence to the idea that autism is caused by a multitude of faulty genes, not just a single mutation, researchers said.
"We do not think that the variants we have identified are monogenic causes of autism," Zwick said. "Our data does support the idea that this is an autism susceptibility gene."
Autism is a development disorder characterized by impaired social and communication skills. Autistic children often have poor social skills, a delay in learning to talk, limited interests in activities and engage in repetitive behaviors, according to the Mayo Clinic.
Autism is typically diagnosed around 3 years of age, but symptoms can be seen as early as 16-months-old. Early intervention consists of therapy to help children walk, talk and interact with others before an official diagnosis is made.
Autism rates have skyrocketed since 2002, according to the Centers for Disease Control and Prevention. In 2002, 1-in-156 children were diagnosed with autism. In 2008, 1-in-88 children were diagnosed, an increase of 78 percent.
The cause of autism is not known, but having a sibling with autism raises the risk. In addition, scientists think there is a genetic factor to the condition.
© 2012 iScience Times All rights reserved. Do not reproduce without permission.