Genetics

DEAR DOCTOR K: I am a 34-year-old woman married to a man more than 20 years my senior. Our first child, a son born four years ago, is autistic. I have heard that older fathers are more likely to have autistic children. Is this true?

DEAR READER: I am not an expert on autism. I have learned what I know from experts here at Harvard Medical School. No one knows the causes of autism, but today the apparent consensus is that they are biological — something a child is born with. As to your question, I'm told that some research has shown that a child's risk of developing autism does rise as the age of the child's biological father rises.