Genetic mutation in autism due to sperm

Genetic mutation in autism caused by sperm

05/04/2012

According to recent study results, the genetic causes of autism are far more complex than previously thought. There are many different forms of autism, the causes of which are only partially known. Scientists found that father's sperm often plays a key role in the autism mutation.

Autism occurs in different forms
Autism is a profound developmental disorder that is considered incurable. Due to the perception and information processing disorder of the brain, autistic individuals are not or only partially able to act socially, depending on their severity and severity. This is particularly evident in contact with their fellow human beings, because they have limitations in the field of non-verbal communication and have little or no ability to establish informal relationships. In addition, sufferers often suffer from stereotypical behaviors. Children who already suffer from autism at an early age often develop no phonetic language or are distracted by language development delays.
Scientists recently found that the cause of autism is much more complex than previously thought. Instead of fewer genes that trigger the developmental disorder, many small changes in the genetic make-up of a child interact.

It is particularly interesting that most mutations are not passed down through generations, but develop only in the sperm and egg cells of the parents or in the genome of the child. In the trade magazine „Nature "three studies have been published on this subject.The scientists report that autism as „Umbrella Disorder“ to describe. There is not only an autism at the molecular level but many different forms whose causes vary greatly. „Like many genetic diseases, autism relies on the activity of many genes, "explains Mark Daly of the Broad Institute of the Massachusetts Institute of Technology (MIT) at Cambridge, who led one of the trials, and only three mutations can be identified comparing the study results which could in themselves trigger the developmental disorder, but researchers found these genes in less than one percent of autistic children.

Many small genetic changes lead to autism in interaction
During the investigations, the scientists were able to identify more than 200 new point mutations. However, these alone could not trigger such severe developmental disorders, they report. However, 49 of the mutant genes are intertwined via a network of proteins that they produce. On the one hand, this network is involved in the formation of brain cells and their connections, and on the other hand, its task is to regulate the packaging and form of the genomic DNA molecule. The researchers found that genes from this network are often disturbed in autistic children. However, a common mechanism can not be derived so far. „So far we have only scratched the surface, "says Daly.

The investigations also showed that the paternal genome plays an essential role. In the more than 200 autistic children examined, it was found that they had received three-quarters of the mutations in the sperm of the fathers. Here, the age of the father is crucial, because the older the father, the higher the probability that he witnessed a child with autism, the researchers said.

In the three studies, the researchers looked at families in which a child had the developmental disorder for the first time. This form of autism is called sporadic and is the most common form of developmental disorder. Both the healthy parents and siblings as well as the autistic child, a part of the genome was analyzed, which includes the blueprints for proteins. The evaluation of the decrypted DNA sequences of the family members made it clear at which points the genetic material of the autistic children was disturbed.

Number of autistic people is increasing
Since the cause of autism is still largely unknown, so far there is no drug with this indication. Concomitants of developmental disorders, which include anxiety, depression and aggressiveness, can be treated with antidepressants or atypical antipsychotics, among others. Other measures such as occupational therapy, behavioral therapy, social skills development and speech therapy can also help.

As early as 2010, that was rejected „Center for Disease Control“ (CDC) indicates that the number of autistic people is increasing significantly. Between 2002 and 2006 it should have come to an increase of 57 percent. Some experts see a link between environmental toxins or vaccine additives and the disease, but so far there is no sound scientific evidence for this assumption. (Ag)

Also read:
Solvents provoke autism in children
Study: Autism already detectable in babies

Image: Martin Gapa