Parental Age May Affect Children's Intelligence
Opposite Effect Of Mother's and Father's Age
It is already well known that increasing parental age is associated with decreased fertility. Unfortunately, increasing parental age has another undesirable effect on the child’s health and should be known to the future parent. Recently, there has been more attention given to the health of offspring of older fathers. As of 1996, a practice guideline has been developed on genetic counseling for advanced paternal age. This has been made public and was updated in 2008 by Dr Toriello and colleagues from Spectrum-Health (Michigan). The report is entitled 'The state of knowledge of advanced paternal age: effects on single gene mutations, chromosome anomalies, and complex traits ' (Genet Med. 2008 Jun;10(6):457-60).
Disorders Associated with Increased Paternal Age
Some of the increased risks of disorders of offspring with older fathers are already known to include children developing a higher risk of Alzheimer disease, Dyslexia, Bipolar disorder and Epilepsy. There is also evidence to suggest increased risk for Schizophrenia and Autism as well as the possibility of fetal death. Other effects include the physical deformity such as Cleft lip and palate
Intelligence of Offspring and Parental Age
The relation between parental age and intelligence has been studied by many groups in the past years and would certainly be of strong interest to new parents. Every parent hopes for a beautiful and an intelligent offspring. Scientists have been interested in the effect of parental age on offspring intelligence, although more for medical consequences than social reasons. However, some discrepancies have been reported among the various studies published and it is not clear whether an increase in the age of the father is beneficial or not.
In March 2009, Dr John McGrath and colleagues, from the Queensland Center for Research (Australia) published in the scientific journal PLoS Medicine, a new study entitled “Advanced paternal age is associated with impaired neurocognitive outcomes during infancy and childhood" (PLoS Med 6(3): e1000040. doi:10.1371/journal.pmed). In this study, scientists have investigated the relationship between the age of both parents (maternal and paternal) on the mental health of the offspring in some 33,000 cases starting at 8 months, 4 years and then 7 years after birth.
Opposite Effects of Maternal and Paternal Age on Intellectual Abilities of Offspring
In their study, John McGrath and colleagues tested the intellectual, neurocognitive abilities of children through different neurological tasks that are adapted to each age group. The purpose of these tasks was to measure the intellectual performance of the children. The scientists reported that the offspring of older fathers tended to show a significant and a constant trend of decreased performance on a range of neurological tasks. In contrast, older mothers have shown an opposite trend whereby the offspring has constantly exhibited a strong increase in abilities to carry out the same neurological tasks.
Is Genetics Involved in the Abilities of Offspring with Older Fathers?
This study raises several questions. For example, how do the social or economic factors affect the parental age and to what degree influence the intellectual abilities of children and what is the impact of social factors as compared to genetic factors? If genetics are involved, as is the case in some medical disorders observed in offspring of older parents, what is the role of genetics in the impaired intellectual abilities of children with older fathers?
In contrast, a positive aspect of this study could be interpreted: women who do decide to start their careers before starting a family, and who plan to conceive later on in life, can rest assured that there is a good chance their offspring may ultimately benefit from their choices in life.
Offspring
|
What do you think about this article?
More in Science & Nature
Latest Articles