I heard some time ago that they believed older men are more likely than younger men to father a child with autism or schizophrenia; but I had not heard anything more on this subject until I read it in an article today on http://www.nytimes.com/2012/08/23/health/fathers-age-is-linked-to-risk-of-autism-and-sc… August 23, 2012, indicating random mutations became more numerous with advancing paternal age, scientists also reported on Wednesday, in its first study to quantify the effect as it builds each year. The age of the mothers did not have a bearing on the risk for these disorders, the study found.
I have a couple of friends who had a child when they were in their early 40’s and one of these friends had a child with Asperger’s syndrome and the other a child with autism. Both of them took the necessary steps early in their children’s childhood to get the necessary support and medical care. The child with Asperger’s was removed repeatedly from many public schools for terrible outbursts to other student and also the teacher and causing total disruption in the classroom; he is now in a private school. The other child with autism is under the care of doctors, counselors, and other help support groups to teach the child how to live a productive and an active life.
According to the article experts believe this overall risk to men in their 40s or older is in the range of 2 percent, and there might be other biological factors existing that are not known at this time. Men do not become alarmed and forgo fatherhood later in life even though this finding may have some effect on reproductive decisions.
In the article it indicated that in a study published online in the journal Nature, providing support for this argument that the increasing rate of autism diagnosed over decades is attributed in part to the increasing average age of fathers; this may account for as many as 20 to 30 percent of the cases.
The article stated findings countered that the longstanding assumption that the mother’s age is the most important factor in determining the odds of a child having developmental problems. The study also found the risk of chromosomal abnormalities, like Down syndrome, did increase for older mothers; and when it comes to some complex developmental and psychiatric problems, the man’s share of genetic risk originates in their sperm and not the egg.
According to the article prior studies strongly suggested this, including an analysis that was published in April found this risk was higher in the men age group of 35 than in men age group of 25 and it does creep up with age. In the new report it quantifies this risk for the first time, it calculated how much it accrued each year.
It also indicated in the article that the research team had an interesting finding in that the average child born to a 20-year-old father had 25 random mutations which could be traceable to paternal genetic material. This number increased gradually by two mutations a year, reaching up to 65 mutations for offspring of 40-year-old-men.
No matter the age of the Mother, the average number of mutations that came from the Mother’s side was 15, according to the study.
According to Dr. Fred R. Volkmar, director of the Child Study Center at the Yale School of Medicine, who was involved in this research, and he stated, “This provided some of the first solid scientific evidence for a true increase in the condition” of autism. “It is extremely well done and the sample meticulously characterized.”
The article stated a new investigation, led by the Icelandic firm Decode Genetics, analyzed genetic material taken from blood sample of 78 parent-child trios. It focused on families with parents who had “no” signs of a mental disorder gave birth to a child who developed autism or schizophrenia. Through this type of approach it allowed scientists to isolate brand-new mutations in the genes of the children that were not present in the parents.
In the article it stated most people having a lot of these so-called de novo mutations that occurred spontaneously at or near the conception and a majority of them are harmless. In recent studies it suggested there are several such changes that can sharply increase the risk of autism and possibly schizophrenia; and the more a child has, the more likely he or she is by chance to have one of these rare, disabling ones.
It also stated some difference between the paternal and maternal side is to be expected. Sperm cells divide every 15 days or so, whereas egg cells are relatively stable, and continual copying inevitable leads to errors, in DNA as in life. When the researches removed the effect of the paternal age, there was “no” difference in the genetic risk between those who had a diagnosis of autism or schizophrenia and a control group of Icelanders who did not.
This is what I found to be profound in the article, Dr. Kari Stefansson, the chief executive of Decode and the study’s senior author indicated it is absolutely stunning that the father’s age accounted for all the added risk, given the possibility of environmental factors and the diversity of the population. Stefansson pointed out that it’s amazing so little contributed to the age of the Mother.
Stefansson also stated that it made sense that de novo mutations would play a significant role in brain disorders. Random glitches are more likely to affect the brain than other organs, which have less exposure because at least 50 percent of the active play a role in neural development.
The article indicated some experts believe the end result of these kinds of mutations might account for 20 to 30 percent of cases of autism, and perhaps schizophrenia; the remainder is possibly the result of an inherited genetic predisposition and environmental factors that are the subjects of numerous studies.
Stefansson and other experts stated that an increase in the average age of fathers had most possibly led to more cases of autism. This study is backed by evidence that scientists agree to be solid; unlike some other theories proposed to explain the increase, such as vaccinations.
In the article it stated this study doesn’t explain the overall increase in diagnoses, at least in the United States. According to government figures, the birthrate of fathers who are 40 and older have increased by more than 30 percent since 1980, but the diagnosis has jumped tenfold, to 1 in 88 (8-year-olds) in a most recent government survey.
It’s not clear as to whether the rate of schizophrenia diagnosis have increased any in that time.
In an editorial accompanying the study, Alexey S. Kondrashov of the University of Michigan wrote if these study findings hold up and extend to other brain disorders, “Then collecting the sperm of young adult men and cold-storing it for later use may be a wise individual decision.”
Evan E. Eichler, a professor of genome sciences at the University of Washington in Seattle, stated this depends on the individual, and said, “You are going to have men who look at this and they will say, ‘Oh no, you mean I have to have all my kids when I’m 20 and stupid?” “Well, of course not. You have to realize that the vast majority of these mutations have “no” consequences, and that there are tons of guys in their 50s who have healthy children.”
Dr. Stefansson’s co-authors included C. Augustine Kong of Decode, and researchers from the University of Iceland, Asrhus University in Denmark, and the company Illumina Cambridge Ltd.
I do hope this article will be helpful to those of you who have been interested in father’s who are concerned about having children after the age of 40 years. They probably had read or heard the same data pertaining to fathers over 40 having children and the dangers of autism and schizophrenia as I did and this will give them some concrete answers.
Photograph Images & Copyrights as follows:
1. wikimedia commons/Countiner
2. wikimedia commons/Emily Walker
3. morguefile.com/Jill Wright