Mutations in the sperm of older men could be a major contributory factor that leads to a significantly higher risk of having children with autism, say researchers from Mount Sinai School of Medicine, New York, USA. They found that men over 40 have a much higher chance of fathering children with autism, compared to men under 30.
In most of the developed world the prevalence of autism among children has more than doubled over the last twenty years from about 18 per 10,000 to 50 per 10,000. Many reasons have been given for this, such as the MMR vaccine, pollution and better diagnosis today.
You can read about this study in the Archives of General Psychiatry, September 2006 issue.
Team leader, Abraham Reichenberg, when talking about the sperm of older men, said “Those mutations might be accumulating with age and therefore transmitted from the father to the child,” He added that it is possible that the mechanisms the body has to protect itself from mutations are not working as well with age. Perhaps a defective gene(s) is being activated as men get older, he said.
The team looked at the ages of the fathers of 318,506 newborns in Israel during the 80s. They also managed to find out what the ages of the mothers were for about 38% of them. The researchers also checked the histories of the men and women for psychiatric disorders.
Here are some of their findings:
— 208 children had autism from data where only fathers’ ages were known
— 110 children had autism where ages of fathers and mothers were known
— 34 children had autism of 60,654 children whose parents were aged 15-29
— 62 children had autism of 67,211 children whose parents were aged 30-39
— 13 children had autism of 4,106 children whose parents were aged 40-49
— 1 child had autism of 190 children whose parents were over 50
— A man over 40 is 5.75 times more likely to have a child with autism than a man under years of age. This is after controlling for year of birth, socioeconomic status, and maternal age
— No link was found between autism in children and the age of the pregnant mother
Some health experts suggest there may be other reasons for the older men’s higher risk of fathering a child with autism. Perhaps a higher percentage of men with mild autism marry later and have children later.
What is Autism?
Autism is the result of a neurological disorder that impacts on the normal functioning of the brain – especially with regard to a person’s social interaction and communication skills. Generally, signs become evident during the first three years of a child’s life. However, I know several people who spotted signs earlier.
A person with autism has difficulties in verbal and non-verbal communication, leisure and/or play activities and social interactions.
Autism is known as a wide-spectrum disorder, i.e. the symptoms of autism can vary widely from one individual to the next.
There are many terms for the different types of autism, from Asperger’s Syndrome, Rett’s Disorder to Autistic Disorder. If you want to get a better understanding, read this web page from The Autism Society.
Although treatment has improved greatly over the past twenty years, autism cannot be cured. It is three to four times more common in boys than in girls.
?Advancing Paternal Age and Autism?
Abraham Reichenberg, PhD; Raz Gross, MD, MPH; Mark Weiser, MD; Michealine Bresnahan, PhD; Jeremy Silverman, PhD; Susan Harlap, MBBS; Jonathan Rabinowitz, PhD; Cory Shulman, PhD; Dolores Malaspina, MD; Gad Lubin, MD; Haim Y. Knobler, MD; Michael Davidson, MD; Ezra Susser, MD, DrPH
Arch Gen Psychiatry. 2006;63:1026-1032
Written by: Christian Nordqvist
Editor: Medical News Today