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.

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 July 22, 2014 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 July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com
Tooth Plaque Provides Insight Into Diets Of Ancient People

Tooth Plaque Provides Insight Into Diets Of Ancient People

Newsy (July 19, 2014) Research on plaque from ancient teeth shows that our prehistoric ancestor's had a detailed understanding of plants long before developing agriculture. Video provided by Newsy
Powered by NewsLook.com
Contaminated Water Kills 3 Babies in South African Town

Contaminated Water Kills 3 Babies in South African Town

AFP (July 18, 2014) Contaminated water in South Africa's northwestern town of Bloemhof kills three babies and hospitalises over 500 people. The incident highlights growing fears over water safety in South Africa. Duration: 02:22 Video provided by AFP
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:
from the past week

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