Autism involves multiple gene interactions, mouse study
February 11, 2009 by Grace Ibay
Filed under Health
Autism researchers have long believed that there is more than one gene involved in autism, and that these genes are interacting with one another to create the spectrum associated with the disorder.
For the first time, scientists at MIT found that mice carrying mutations in two candidate genes for autism have more severe symptoms than those with only one mutation. The two genes studied were PTEN and serotonin transporter. In female mice, mutations in PTEN impaired sociability while those who also had mutations in the serotonin gene had worse symptoms.
"We found that two genetic risk factors for autism spectrum disorders (ASDs) act cooperatively in mice to influence brain size and social behavior, both of which are altered in ASDs," said Damon T. Page, a Picower Institute postdoctoral fellow and lead investigator of the study, which appeared in the February 10 issue of PNAS.
If this result translates to humans, the interaction of these genes could serve as biomarkers for certain subsets of individuals with ASD. It will also mean that drugs for the treatment of autism would need to target multiple genes.
Read details of the report at – Multiple Genes Implicated In Autism; Discovery Could Lead To Drugs Targeting Gene Interactions
Thoughts Regarding Autism Spectrum Neurodevelopmental Disorders
Of these rare neurological disorders, Autism is the most common. The autism spectrum reflects the broad range of symptoms in which the names of these autism disorders have been given their own name for their disorder.
Autism is a disability that is suspected to be caused possibly by a brain development disorder of unknown etiology. Others suspect the cause is some sort of neurological dysfunction- possibly with a genetic predisposition. Autism is about 3 times more common in males than females as well, and it is unclear as to why this occurs.
Usually, symptoms of the disease present themselves before the toddler reaches the age of three. Before Autism was more understood, others inaccurately labeled autistic people as childhood schizophrenia or as having a psychosis or mental retardation.
Symptoms of the autistic patient included limited or dysfunctional social and personal or intimate relationships with others, their intelligence is affected, and the autistic person typically is adverse to change. Also, the autistic person tends to be compulsive and prefers to be alone. They lack eye contact as much as physical contact with other people.
Out of over two dozen diagnostic criteria utilized for these disorders, eight must be present to be considered autistic, according to the DSM. As with all passive developmental disorders, the person expresses language, social, and behavioral difficulties.
Treatment includes what are called psychotropic medications that delay the progression of the disorder, as well as relieve some of the symptoms of one who is autistic. Behavioral therapy is common as a treatment regimen as well. Boys get Autism much more than girls.
Then there is the controversy between many who claim that thimerosal- a preservative containing mercury, which is a neurotoxin that was used in vaccines until 2001, was the catalyst for autism in children.
Over 5000 lawsuits have been filed because of this belief, and some have been successful for the plaintiff. Yet most agree the correlation between thimersal and autism is void of scientific merit. Furthermore, the cases of autism have not decreased since the preservative was discontinued in 2001.
Aside from Autism, the other four passive developmental disorders are known as autism spectrum disorders.
Asperger’s Syndrome is more common than autism, and the symptoms are milder, as there is minimal delay in language abilities, if at all. What is expressed with Asperger’s syndrome is mild autistic symptoms. In time, the patient may express atypical personality disorders, though.
While intelligence is within normal limits with the Asperger’s patient, social interactions and abilities preset difficulty for such a patient. As with Autism, medications and behavioral therapy are treatment regimens with one with this syndrome
Rett’s Syndrome or disorder presents with not only atypical behavior, but also suffers from restricted physical growth and movement. There is cognitive and social impairment as well. The disorder affects mostly girls, and the cause is due to a gene mutation.
Childhood Disintegrative disorder is rare, and is 10 times less common than autism. The disorder has a late onset with mild autistic symptoms. The disorder affects mostly boys, and regression is sudden and possible with this disorder. Skills lost with this disorder may be language, social, self-care, as well as play or motor skills. Decreased function or impairment with this disorder may include social skills and behavioral flaws. Central Nervous System pathology is a suspected cause of this disorder.
Finally, there are passive development disorders that are not otherwise specified. This may include atypical autism, for example. Yet as with the rest of types of these disorders, the symptoms vary in their frequency and intensity, as well as the range of abilities of these developmental disorders vary widely as well.
Medicinal treatment is believed to be not necessary for the management of all of those who may have autistic spectrum disorders. Depending on the patient’s health care provider, medications may be prescribed by their doctor to manage any affective disorders autistics may present in an acute or chronic nature. However, cognitive and behavioral therapy prove to be most beneficial for all the different types of Passive Development Disorders that exist for reasons yet to be defined.
http://www.autism-society.org
Dan Abshear