Men who father children when they are 40 or older are significantly more likely to have autistic children than younger fathers.
A study of 130,000 Israelis born in the 1980s showed that those with older fathers were almost 600 percent more likely to be autistic than those with fathers under 30, and more than half again as likely to be autistic as those with fathers aged 30-39.
The study was based on information collected when, at 17; Israeli boys and girls are assessed for military eligibility.
Previous research has also commented paternal age with lower intelligence scores and schizophrenia. Sperm mutate more often in older men, which may account for the increased risk of brain abnormalities.