WEDNESDAY, Aug. 22 (HealthDay News) -- Men who have kids later in life may pass on more new genetic mutations to their offspring, possibly raising their child's risk of disorders such as autism and schizophrenia, new research suggests.
New mutations arise in the sperm cells of men near the time of conception instead of being passed down through generations. They have been associated with relatively rare cases of non-hereditary autism.
Researchers in Iceland searched the genomes of 78 families for new mutations as they first appeared and looked at how the number of these mutations in children was related to the age of their parents. In most of the families, the child had either non-hereditary autism or schizophrenia.
The study, which was published Aug. 22 in the journal Nature, found that every year a man ages, he is predicted to pass on more than two additional new (or "de novo") mutations. More than 97 percent of these new mutations in children were explained by having an older dad.
"The father is an incredibly important contributor to mutations, and even if de novo mutations happen randomly, the more mutations you have, the more likely you will have one in a gene that matters," said study author Dr. Kari Stefansson, CEO of deCODE Genetics, a genome analysis company based in Reykjavik, Iceland.
Previous research has linked higher rates of spontaneous mutations to older dads based on the sequence of select regions of the genome; this study is the first to make the connection based on data from the entire genome of parents and their children, Stefansson said.
"This study further establishes that paternal age is a risk factor for [non-hereditary] autism," said Daniel Smith, senior director of discovery neuroscience at Autism Speaks, an autism research and advocacy organization.
Although it is not known how many cases are autism are non-hereditary,
All rights reserved