Younger siblings of those with autism are over a dozen times more likely than other kids to have the developmental disorder too, a new study suggests.
The risk did not appear to be affected by a child’s race or whether they were born early, at term or late. However, gender did seem to make a difference, according to findings published online this month in the Journal of Developmental & Behavioral Pediatrics.
Among kids with an older sibling on the spectrum, 11.3 percent were ultimately diagnosed with autism as well. By comparison, just 0.92 percent of other children were found to have the developmental disorder.
The risk was higher for boys with older brothers with autism — 15 percent — compared to girls with affected older sisters who were diagnosed 7 percent of the time, the study found.