Moms aren’t the only ones who pose a risk when they wait to have children. A new study suggests that older dads are responsible for some children developing intellectual disabilities.

In a study of 118 children with intellectual disability caused by a missing, repeated or an otherwise abnormal DNA sequence, Dutch researchers found that in most cases the problem originated with the father’s sperm.

What’s more, the study found that men who had the problematic sperm were often in their 40s and 50s.

The findings, published this month in the Journal of Medical Genetics, are the first to link intellectual disability and older fathers, though paternal age has previously been tied to other conditions like schizophrenia.

Other forms of intellectual disability such as Down syndrome, which occurs when a person has an extra chromosome, are associated with older mothers, reports The (Toronto) Globe and Mail. To read more click here.