Featured Research

from universities, journals, and other organizations

Amount of gene surplus determines severity of mental retardation in males, researchers find

Date:
December 14, 2009
Source:
VIB (the Flanders Institute for Biotechnology)
Summary:
Researchers have discovered a new explanation for differences in the severity of mental illness in males. The more excess copies of a certain gene, the more serious the handicap. The genetic defect is situated on the X-chromosome; and it is suspected that it is the amount of copies of the GDI1 gene that is responsible.

Researchers have discovered a new explanation for differences in the severity of mental illness in males. The more excess copies of a certain gene, the more serious the handicap. The genetic defect is situated on the X-chromosome; and it is suspected that it is the amount of copies of the GDI1 gene that is responsible.

Related Articles


The results are being published in the American Journal of Human Genetics, and are the result of work by the group of Guy Froyen connected to VIB, a life sciences research institute in Flanders, Belgium at the University of Leuven, in close collaboration with Hilde Van Esch of the Center for Human Genetics (University Hospital Leuven) and colleagues in Germany and Spain.

It is for first time that scientists have linked the degree of a mental illness to the number of copies of a gene on the X-chromosome, normally present as a single copy in males. The mental handicap is much more severe in patients with 5 copies than in patients with 2 copies. An intermediate severity has been observed in case of 3 copies. In their publication, the scientists also present a new mechanism by which such defects can arise. This mechanism might also underlie other genetic disorders.

Differences in GDI1 production

Defects in the GDI1 gene have previously been found in a few XLMR (X-Linked Mental Retardation) patients. In these patients, the production of GDI1 in the brain is disturbed, which impedes the transfer of stimuli in the brain. The new finding in this research is that over-production of GDI1 is also harmful. The higher the production, the greater the disruption of signals.

Only in male patients

The discovery was made through DNA research in several families in which only males are afflicted with a mental handicap. In such families, defects appear on the X-chromosome (thus the name X-Linked Mental Retardation). Males have only one version of the X-chromosome. Females have a reserve copy, through which defective information can be masked.

2 -- 3% of the population has a mental handicap

Mental handicap occurs in 2 -- 3% of the population. The handicap can be attributed to external factors, such as a deficiency in oxygen at birth, or to defects in the DNA. When the cause is genetic (hereditary), exact identification of the defect is crucially important for providing the patient with the proper medical support or for assessing the risk involved for couples with child wish. Recent estimates are that a defect on the X-chromosome is the cause in about 12% of the patients. However, in over half of the XLMR patients, the responsible gene has not yet been identified. This research makes a contribution toward filling this gap in our knowledge.


Story Source:

The above story is based on materials provided by VIB (the Flanders Institute for Biotechnology). Note: Materials may be edited for content and length.


Cite This Page:

VIB (the Flanders Institute for Biotechnology). "Amount of gene surplus determines severity of mental retardation in males, researchers find." ScienceDaily. ScienceDaily, 14 December 2009. <www.sciencedaily.com/releases/2009/12/091210125922.htm>.
VIB (the Flanders Institute for Biotechnology). (2009, December 14). Amount of gene surplus determines severity of mental retardation in males, researchers find. ScienceDaily. Retrieved March 31, 2015 from www.sciencedaily.com/releases/2009/12/091210125922.htm
VIB (the Flanders Institute for Biotechnology). "Amount of gene surplus determines severity of mental retardation in males, researchers find." ScienceDaily. www.sciencedaily.com/releases/2009/12/091210125922.htm (accessed March 31, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Tuesday, March 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Soda, Salt and Sugar: The Next Generation of Taxes

Soda, Salt and Sugar: The Next Generation of Taxes

Washington Post (Mar. 30, 2015) — Denisa Livingston, a health advocate for the Dinι Community Advocacy Alliance, and the Post&apos;s Abby Phillip discuss efforts around the country to make unhealthy food choices hurt your wallet as much as your waistline. Video provided by Washington Post
Powered by NewsLook.com
UnitedHealth Buys Catamaran

UnitedHealth Buys Catamaran

Reuters - Business Video Online (Mar. 30, 2015) — The $12.8 billion merger will combine the U.S.&apos; third and fourth largest pharmacy benefit managers. Analysts say smaller PBMs could also merge. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
S. Leone in New Anti-Ebola Lockdown

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17 Video provided by AFP
Powered by NewsLook.com
These Popular Antibiotics Can Cause Permanent Nerve Damage

These Popular Antibiotics Can Cause Permanent Nerve Damage

Newsy (Mar. 27, 2015) — A popular class of antibiotic can leave patients in severe pain and even result in permanent nerve damage. 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