Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene discovered to cause rare, severe neurological disease

29.11.2016

Epileptic encephalopathy linked to protein trafficking gene

Researchers have linked a debilitating neurological disease in children to mutations in a gene that regulates neuronal development through control of protein movement within neuronal cells.


A neuron in culture was transduced with a virus that expresses a green fluorescent protein and an inhibitory RNA that causes loss of the DENND5A protein. The neurons where then stained with a marker of neuronal processes in red.

Credit: Peter McPherson Lab, Montreal Neurological Institute

The scientists from the Montreal Neurological Institute and Hospital at McGill University, led by Peter McPherson, along with collaborators in Saudi Arabia, Jordan, Germany, and at SickKids Hospital and the University of Toronto, have discovered that a severe form of epileptic encephalopathy is caused by recessive loss-of-function mutations in the gene DENND5A. Their findings were published in the American Journal of Human Genetics on Nov. 17.

Epileptic encephalopathy is a rare but devastating sub-form of epilepsy that results in severe mental and physical disabilities in children from birth. It is often caused by improper development of the brain. Individuals with epileptic encephalopathy caused by mutations in DENND5A present with serious anomalies in brain structure along with calcifications in the brain and altered facial features.

Researchers performed whole exome sequencing on three children with epileptic encephalopathy from two families, one from Saudi Arabia and another from Jordan. Both families were consanguineous, meaning the parents were related to each other. This greatly increases the chance that rare mutations that are recessive and that cause no harm to the parents are expressed in the children.

The whole exome sequencing, along with extensive and complex genetic analysis, revealed that recessive mutations in DENND5A were responsible for the disease, with the Saudi family and the Jordanian family having different mutations but in the same DENND5A gene.

They found that mutations in DENND5A lead to a lack of the DENND5A protein, resulting in underdevelopment of the central nervous system. The protein expressed from the DENND5A gene is present at highest levels in the nervous system especially while the brain is developing, corroborating the evidence that mutations in the gene cause epileptic encephalopathy.

The researchers discovered that the DENND5A protein controls the movement of receptors for key developmental factors called neurotrophins. Disruption of DENND5A function leads to altered levels of these receptors, which could explain why loss of DENND5A leads to the severe neurological developmental defects in the patients.

Epilepsy affects approximately three per cent of the world population, and epileptic encephalopathy is a rare sub-form of the disease. It is difficult to say how many children with epileptic encephalopathy have the DENND5A mutations, but now that the gene has been identified as a cause, researchers around the world can begin to test patients for mutations in this gene.

This finding also improves our understanding of neuronal development. The observation that loss-of-function mutations in DENND5A causes epileptic encephalopathy suggests that DENND5A protein controls membrane trafficking pathways critical for normal neuronal development and strengthens the argument that protein trafficking processes in cells are critical for normal neuronal development and function.

"Our study demonstrates the importance of membrane trafficking in neuronal development and it provides a new pathophysiological mechanism for this disease type. This will allow physicians around the world to test if mutations in DENND5A are causing the disease in their patients, and also to provide genetic counselling for affected families," says Dr. Chanshuai Han, the lead author on the study.

###

This research was funded with the help of the Canadian Institutes for Health Research, the German Academic Exchange Service, the Ontario Brain Institute, Genome Canada, and the Fonds de recherché Quebec, Santé.

Peter McPherson, the senior author on the study, is a James McGill Professor and a Fellow of the Royal Society of Canada.

Media Contact

Shawn Hayward
shawn.hayward@mcgill.ca
514-398-3376

 @McGillU

http://www.mcgill.ca 

Shawn Hayward | EurekAlert!

Further reports about: epileptic nervous system neurological disease trafficking

More articles from Health and Medicine:

nachricht How cancer metastasis happens: Researchers reveal a key mechanism
19.01.2018 | Weill Cornell Medicine

nachricht Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

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...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

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...

Im Focus: Room-temperature multiferroic thin films and their properties

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>