Older fathers link to child brain
Gene mutations tend to be more common in older fathers
Children of older fathers perform less well in a range of brainpower tests during infancy and early childhood, a study found.
In contrast, children with older mothers did well on the tests, which assessed abilities such as memory, learning and concentration.
Experts believe mutations in a man's sperm, which build over time, may be a factor.
The University of Queensland study appears in the journal PLoS Medicine.
Nature intended us to have our children earlier in our lives than we currently are
Dr Allan PaceyUniversity of SheffieldThe age at which men and women are having children is increasing in the developed world.
But while the effect of increasing maternal age on reduced fertility is widely known, the impact of increased paternal age is not as well established.
However, older fathers have been linked to a range of health problems, including an increased risk of birth deformities and neuropsychiatric conditions, such as schizophrenia, autism and bipolar disorder.
The Queensland team analysed data on 33,437 children born between 1959 and 1965 in the US.
Each child was given a range of tests of cognitive function at eight months, four years, and seven years.
The researchers adjusted their study to take account of socio-economic factors, such as family income and parental education.
They found that the older the father, the more likely the child was to have lower scores on the various tests.
In contrast, the older the mother the higher the scores of the child in the cognitive tests.
Nurturing environment
Previous researchers have suggested children of older mothers may perform better because they experience a more nurturing home environment.
But the latest study suggests this might not be the case in relation to fathers.
Genetic factors are likely to be key, as there is evidence that genetic mutations become more widespread in a man's sperm as he ages.
But the Queensland team said the impact of social factors could also not be ruled out, although they said a child would usually benefit socioeconomically from having an older father, with better access to health and educational services.
The researchers, led by Dr John McGrath, wrote: "Given the trend towards older maternal and paternal ages in the developing world, policy-makers may want to consider promoting an awareness of the risks to children that this study associates with delayed fatherhood."
Dr Allan Pacey, an expert in fertility at the University of Sheffield, said: "We have known for some time that the children born from older fathers are at increased risk of a number of medical problems and this is almost certainly because as men get older the sperm production gets less efficient and their sperm have a higher number of genetic defects.
"The author's observation that most neurocognitive outcomes is also reduced in the children of older fathers provides a further piece of evidence to remind us that nature intended us to have our children earlier in our lives than we currently are."
Hi I read you have published a report that says children from older fathers tend to have higher rates of autism, and differences in cognitive functions at eight months, four years, and seven years. Your explanation is mutations in sperm but is not possinbe that the explanation for your results, is simply the passing on of genetic traits, that would be there regarldless of what age they had had children at, but that people with these cognitive issues would take longer to have children in first place.
ReplyDeleteIs this because men with these problems in the first place would take longer to get into the work place and develop a strong financial footing to have children, and also to develop realtionships, to then pass on these traits. While men without these issues would be having children at a younger age, due to their higher ability to form relationships.
Do you not think it possible that you are putting the cart before the horse in the explanation for your results. A good way to test this would be to test children from, the same parents. Otherwise there may be other factors. Also read up Simon Baron Cohen on autism, he says autism is more to do with having a male brain which ties into what i am saying. That men with these more autistic less socially skilled brains, would surely take longer to learn how to develop relationship skills.
Basically I am saying are you saying that
your theory is
1) Mutations in the sperm, cause these issues well why would mutations in sperm cause a more male orientated brain.
My view would be perhaps
2) Men with these mental issues take longer to form relationships and to pass on these traits.
I think you should test this otherwise policiy makers may just punish people and perhaps force people to have children when they do not want to or to bring in laws them stop them altogether on a false premise.;