LOS ANGELES — Men who become fathers later in life pass on more brand-new genetic mutations to their offspring, a study has found — probably contributing to disorders such as autism and schizophrenia in the next generation.
The finding, published online Wednesday in the journal Nature, buttresses earlier observations that rates of autism and some other disorders are more prevalent in children born of older fathers, sometimes by a factor of two or more, experts said. Although this has been observed for years from population studies, scientists had not known what lay behind it.
The research was made possible by advances in DNA-sequencing technology. Although older mothers are more likely to have children with chromosomal disorders such as Down syndrome, the study found that practically all of the new mutations detected in children came from the father.
A man aged 29.7 at the time he fathered a child contributed 63 new mutations on average to his offspring, the authors found, and a man age 46.2 contributed 126 mutations.
