Featured Research

from universities, journals, and other organizations

Gene mutation, key symptoms of autism appear to be linked

Date:
April 25, 2014
Source:
Scripps Research Institute
Summary:
Abnormal brain growth is associated with autism spectrum disorder -- this scientists know. However, the relationship between the two has not been well understood. Now, research has shown that mutations in a specific gene that is disrupted in some individuals with autism results in too much growth throughout the brain, and yet surprisingly specific problems in social interactions, at least in mouse models that mimic this risk factor in humans.

Scientists have known that abnormal brain growth is associated with autism spectrum disorder. However, the relationship between the two has not been well understood.

Now, scientists from the Florida campus of The Scripps Research Institute (TSRI) have shown that mutations in a specific gene that is disrupted in some individuals with autism results in too much growth throughout the brain, and yet surprisingly specific problems in social interactions, at least in mouse models that mimic this risk factor in humans.

“What was striking is that these were basically normal animals in terms of behavior, but there were consistent deficits in tests of social interaction and recognition—which approximate a major symptom of autism,” said Damon Page, a TSRI biologist who led the study. “This suggests that when most parts of the brain are overgrown, the brain somehow adapts to it with minimal effects on behavior in general. However, brain circuits relevant to social behavior are more vulnerable or less able to tolerate this overgrowth.”

The study, which focuses on the gene phosphatase and tensin homolog (PTEN), was recently published online ahead of print by the journal Human Molecular Genetics.

Autism spectrum disorder is a neurodevelopmental disorder involving a range of symptoms and disabilities involving social deficits and communication difficulties, repetitive behaviors and interests, and sometimes cognitive delays. The disorder affects in approximately one percent of the population; some 80 percent of those diagnosed are male.

In a previous study, Page and colleagues found that mutations in Pten causes increased brain size and social deficits, with both symptoms being exacerbated by a second “hit” to a gene that regulates levels of the neurotransmitter serotonin in the brain. In the new study, the TSRI team set out to explore whether mutations in Pten result in widespread or localized overgrowth within the brain, and whether changes in brain growth are associated with broad or selective deficits in tests of autism-relevant behaviors in genetically altered mice. The team tested mice for autism spectrum disorder-related behaviors including mood, anxiety, intellectual, and circadian rhythm and/or sleep abnormalities.

The researchers found that Pten mutant mice showed altered social behavior, but few other changes—a more subtle change than would have been predicted given broad expression and critical cellular function of the gene.

Intriguingly, some of the more subtle impairments were sex-specific. In addition to social impairments, males with the mutated gene showed abnormalities related to repetitive behavior and mood/anxiety, while females exhibited additional circadian activity and emotional learning problems.

The results raise the question of how mutations in PTEN, a general regulator of growth, can have relatively selective effects on behavior and cognitive development. One idea is that PTEN mutations may desynchronize the normal pattern of growth in key cell types—the study points to dopamine neurons—that are relevant for social behavior.

“Timing is everything,” Page said. “Connections have to form in the right place at the right time for circuits to develop normally. Circuitry involved in social behavior may turn out to be particularly vulnerable to the effects of poorly coordinated growth.”


Story Source:

The above story is based on materials provided by Scripps Research Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. E. Clipperton-Allen, D. T. Page. Pten haploinsufficient mice show broad brain overgrowth but selective impairments in autism-relevant behavioral tests. Human Molecular Genetics, 2014; DOI: 10.1093/hmg/ddu057

Cite This Page:

Scripps Research Institute. "Gene mutation, key symptoms of autism appear to be linked." ScienceDaily. ScienceDaily, 25 April 2014. <www.sciencedaily.com/releases/2014/04/140425091843.htm>.
Scripps Research Institute. (2014, April 25). Gene mutation, key symptoms of autism appear to be linked. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2014/04/140425091843.htm
Scripps Research Institute. "Gene mutation, key symptoms of autism appear to be linked." ScienceDaily. www.sciencedaily.com/releases/2014/04/140425091843.htm (accessed October 1, 2014).

Share This



More Mind & Brain News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

App Teaches Kindergarteners to Code

App Teaches Kindergarteners to Code

AP (Oct. 1, 2014) They can't all read yet, but soon kindergarteners may be able to create basic computer code. Researchers in Massachusetts developed an app that teaches young kids a simple computer programming language. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
Your Spouse's Personality May Influence Your Earnings

Your Spouse's Personality May Influence Your Earnings

Newsy (Sep. 26, 2014) Research from Washington University suggest people with conscientious spouses have greater career success. Video provided by Newsy
Powered by NewsLook.com
Can A Blood Test Predict Psychosis Risk?

Can A Blood Test Predict Psychosis Risk?

Newsy (Sep. 26, 2014) Researchers say certain markers in the blood can predict risk of psychosis later in the life. The test can aid in early treatment for the condition. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins