Autistic children from low-income families are undercounted and underserved, a gap community leaders are working to bridge.

About 1 in 40 children in the United States has autism, according to a survey conducted in 2016. Roughly 30 percent of those children were not being treated for the condition at the time.

The rising prevalence of autism is not leveling off, according to a new study that accounts for every diagnosis made in Denmark over 32 years.

A remote Colombian town is home to the world’s largest cluster of people with fragile X syndrome. Scientists are learning from them — and trying to help.

The network of researchers keeping tabs on autism prevalence in U.S. children plans to follow up with some of those children in adolescence.

How researchers design autism prevalence studies has a significant impact on the results, says Eric Fombonne.

About 1 in 100 children in India under age 10 may have autism, and nearly 1 in 8 at least one neurodevelopmental condition.

About 10 percent of people with a large mutation in chromosome 22 have autism, attention deficit hyperactivity disorder or intellectual disability.

More boys than girls have autism; diagnostic biases and genetic factors may explain the skewed sex ratio.

The bulk of the increase in autism prevalence in the United States between 2000 and 2012 can be attributed to children on the mild end of the spectrum.