The recent CDC report on autism rates, which found that one in 88 children may have autism, left many people asking why.
Three studies published in Nature may provide one answer, at least in some cases. These researchers found several gene mutations that increase a child's risk of developing autism and that the risk increases with older parents, especially if a child's father is over 35 years old.
Although these genetic mutations are rare, some experts think that we will find many more mutations in the next few years.
Of course that doesn't mean that researchers will stop looking for other causes and associations.
To highlight that fact, a new study is being published in the May issue of Pediatrics, "Maternal Metabolic Conditions and Risk for Autism and Other Neurodevelopmental Disorders," that looked at children in the Childhood Autism Risks from Genetics and the Environment (CHARGE) study.
The researchers found "a strong association between metabolic conditions during pregnancy (diabetes, obesity and hypertension), and autism spectrum disorder or developmental delays." Specifically, of 1,004 children aged 2 to 5 years in the study, 517 children had autism, 172 children had other developmental disorders, and 315 were developing typically, and obese mothers had 1.6 times the chance of having a child with autism, and were more than twice as likely to have a child with another developmental disorder. Mothers with diabetes were 2.3 times more likely to have a child with developmental delays.
The researchers conclude that "the rising rates of obesity and diabetes may be directly associated with neurodevelopmental problems in children, and that these data, therefore, raise serious public health concerns."