NEW YORK -- The government has a new estimate for autism - 1 in 45 U.S. children.
But other federal calculations say the developmental disorder is less common.
The latest figure released is one of three estimates that the Centers for Disease Control and Prevention gives for autism based on different surveys.
The most rigorous survey has a lower estimate of 1 in 68 children.
The cause or causes of autism are still not known.
Latest US estimate suggests 1 in 45 children have autism