Father's age may increase the risk of autism according to research that attempted to measure the number of genetic mutations in sperm verses egg.

In cases of autism not linked to a family history of the condition, genetic mutations that might account for autism increase along with the age of the father, but not so much the age of the mother according to whole-genome research conducted in Iceland.  The study looked at the genomes of sets of parents and their child to measure the number of unique mutations present in the child's genome that may be attributed to the father's sperm verses the mother's egg.  Sperm are produced throughout the father's reproductive years through continuous cell division, but the mother's eggs are produced prior to her birth and do not undergo further cell division until fertilized.  The implication that logically follows is that with each cycle of cell division the opportunity for new mutations to be introduced increases the likelihood that a father's sperm will pass on mutations linked to conditions including autism and schizophrenia.  Watch a report on the new research at cbsnews.com here:
http://www.cbsnews.com/8301-18563_162-57498675/study-fathers-age-a-likely-factor-in-autism/
Read the article reporting on the research at nature.com here:
http://www.nature.com/news/fathers-bequeath-more-mutations-as-they-age-1.11247