For the studies - published in the June 9 issue of "Neuron" - scientists looked for mutated DNA segments among genetic samples from more than 1,000 families with an autistic child. They found that children with autism had more of these mutations - known as copy number variants - than their autistic-free siblings.
"Before, it was like looking at the map of the United States. There was good enough resolution to tell the states and the big cities," Dr. Christian Schaaf, an assistant professor in the department of molecular and human genetics at the Baylor College of Medicine told HealthDay. "Now, the resolution is so much higher, you can look at individual streets."
Examining these "streets" is what led researchers to discover that boys are more vulnerable to the genetic mutations found in autism.
"It seems to take more hits or more damage to the genome to lead to autism in girls than in boys," Dr. Andy Shih, vice president of scientific affairs for the advocacy group Autism Speaks, told HealthDay." That may start to explain some of the sex biases, that boys are more vulnerable genetically." Boys are 4 to 5 times more likely to be diagnosed with autism than girls.
Will these findings lead to a cure?
"This type of knowledge is a critical first step in developing novel treatment approaches," Dr. Michael Wigler, professor from Cold Spring Harbor Laboratory, N.Y., said in a written statement.
One out of every 110 children has an autism spectrum disorder (ASD). People with an ASD may experience difficulties with social interaction, communication, intelligence, or behavior.
The CDC has more on autism spectrum disorders.