They said their achievement offers the potential for treatment of the disorder, the most common form of inherited mental retardation and a leading identified genetic cause of autism. There is currently no treatment or therapy for fragile X syndrome, whose symptoms include mental retardation, epilepsy, and abnormal body growth.
Mark Bear and colleagues reported their findings in an article in the December 20, 2007, issue of the journal Neuron, published by Cell Press.
Fragile X syndrome is known to be caused by loss of the gene for “fragile X mental retardation protein” (FMRP), which is believed to act as a brake on protein synthesis in specific areas of brain circuitry. The authors’ idea was that loss of the “brake” would allow another protein that stimulates this process, called metabotropic glutamate receptor 5 (mGluR5), to function unchecked.
In their experiments to test this idea, the researchers studied mice that produce many of the characteristic pathologies of fragile X in humans due to a loss of the FMRP gene. The critical test, though, was when they also created double mutant mice that lacked both the FMRP gene and had a 50% reduction in mGluR5. They chose only to reduce the activity of the metabotropic glutamate receptor gene, rather than eliminate it, in order to reflect what might be achieved using drug treatment for fragile X in humans.
Their tests on the double mutant mice revealed that the mGluR5 gene reduction greatly alleviated many abnormalities produced by loss of FMRP. The double mutant mice showed a rescue of abnormalities in brain structure and function, brain protein synthesis, memory, and body growth.
For example, loss of the FMRP gene produces overgrowth of the connections among neurons called dendritic spines. However, the additional 50% reduction in mGluR5 gene produced mice with completely normal spine density.
The double mutants also showed substantial reduction in epileptic seizures caused by lack of FMRP, found the researchers.
They concluded that “it is remarkable that by reducing mGluR5 gene dosage by 50%, we were able to bring multiple, widely varied fragile X phenotypes significantly closer to normal.”
They also concluded that “These findings have major therapeutic implications for fragile X syndrome and autism.”
Cathleen Genova | EurekAlert!
New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego
Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
17.01.2018 | Ecology, The Environment and Conservation
17.01.2018 | Physics and Astronomy
17.01.2018 | Awards Funding