Navigation Links
Amount of gene surplus determines severity of mental retardation in males

Leuven, 10 December 2009 -- 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.


Contact: Joris Gansemans
VIB (the Flanders Institute for Biotechnology)

Related biology technology :

1. Onyx Pharmaceuticals Announces Pricing of Concurrent Offerings of Four Million Shares of Common Stock and $200 Million Principal Amount of Convertible Senior Notes
2. TransTech Services Partners, Inc. Shareholders Approve Plan of Liquidation; Company To Distribute Amounts in Trust
3. ViroPharma Improves Financial Position Through Repurchase of $45 Million Principal Amount of Senior Convertible Notes
4. AlloSource Distributes Record Amount of Tissue in 2008
5. Simbionix Raises Largest Amount in Companys History in Venture Capital to Accelerate Growth
6. Paramount Stockholders Approve Acquisition of Chem Rx
7. Chem Rx to Present at the Paramount BioSciences Healthcare Conference
8. VioQuest Pharmaceuticals to Present at the Paramount BioSciences Healthcare Conference
9. Cutanea to Present at the Paramount BioSciences Healthcare Conference
10. Not the protein, but its location in the cell, determines the onset of leukemia
11. Court Determines that University of Pittsburgh and Artecel Have Sole Rights to Adipose-Derived Stem Cell Patent
Post Your Comments:
(Date:10/11/2017)... LINDA, CA (PRWEB) , ... October 11, 2017 ... ... to upregulate any gene in its endogenous context, enabling overexpression experiments and avoiding ... (CRISPRa) system with small RNA guides is transformative for performing systematic gain-of-function studies. ...
(Date:10/11/2017)... ... October 11, 2017 , ... Proscia Inc ., a ... Webinar titled, “Pathology is going digital. Is your lab ready?” with Dr. Nicolas ... practices and how Proscia improves lab economics and realizes an increase in diagnostic ...
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are the main ... people each year. Especially those living in larger cities are affected by air pollution ... of the most pollution-affected countries globally - decided to take action. , “I knew ...
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building ... corporate rebranding initiative announced today. The bold new look is part of a ... company moves into a significant growth period. , It will also expand its service ...
Breaking Biology Technology:
(Date:8/15/2017)...   ivWatch LLC , a medical device company focused on ... receipt of its ISO 13485 Certification, the global standard for medical ... Standardization (ISO®). ... Continuous Monitoring device for the early detection of IV infiltrations. ... "This is an important milestone for ivWatch, as ...
(Date:6/23/2017)... ARMONK, N.Y. and ITHACA, N.Y. ... IBM ) and Cornell University, a leader in dairy ... combined with bioinformatics designed to help reduce the chances ... breaches. With the onset of this dairy project, Cornell ... the Consortium for Sequencing the Food Supply Chain, a ...
(Date:5/16/2017)... , May 16, 2017  Veratad Technologies, LLC ( ... online age and identity verification solutions, announced today they ... Conference 2017, May 15 thru May 17, 2017, in ... and International Trade Center. Identity impacts ... and in today,s quickly evolving digital world, defining identity ...
Breaking Biology News(10 mins):