Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Elusive gene discovered that makes platelets grey

26.07.2011
Researchers have identified an elusive gene responsible for Grey Platelet Syndrome, an extremely rare blood disorder, which is hoped will make it easier to diagnose

Researchers have identified an elusive gene responsible for Grey Platelet Syndrome, an extremely rare blood disorder in which only about 50 known cases have been reported. As a result, it is hoped that future cases will be easier to diagnose with a DNA test.

The findings were made following a collaborative study by Professor Willem Ouwehand and Dr Cornelis Albers, who are both based at the Wellcome Trust Sanger Institute and the University of Cambridge, and Dr Paquita Nurden, from the Rare Platelet Disorders laboratory, based in Bordeaux, who have described their study.

Platelets are the second most abundant cell in the blood. Their main task is to survey the blood vessel wall for damage and to orchestrate its repair where required. On the flip side, platelets also play a "darker" role after vessel wall damage and cause blood clots that may lead to heart attacks or stroke.

Some people are born with platelets that do not function well and these rare conditions are thought to be inherited. Grey Platelet Syndrome poses a risk of bleeds, some of which can be severe and life threatening, e.g. if they occur in the brain. Grey Platelet Syndrome was first identified in the 1970s and is named for the greyish appearance of these platelets when viewed with a microscope.

Identifying the cause of increased bleeding in young patients has been a painstaking process. An important step in translating research findings in human genetics in improvements of patient care has focused around the need to develop simpler and rapid DNA-based diagnostic test. To achieve this, researchers needed to discover the gene responsible for the rare platelet bleeding disorders.

In the past it was a major challenge to discover which genes caused rare disorders because DNA samples from numerous large families affected by the same disorder had to be identified and genetically analysed to pinpoint the region harbouring the causative gene.

To achieve their latest findings, researchers used a simpler approach and deciphered about 40 million letters of genetic code covering the entire coding fraction of the genome of four non-related French patients.

They identified the gene NBEAL2 as not functioning well in Grey Platelet Syndrome, a member of a family of genes that all contain a unique domain, called the BEACH domain. The team showed that protein encoded by this gene is altered at a different position in the four non-related cases and the patients affected by the disorder have inherited two non-functioning copies of the gene, one from father and mother each.

"It is really great to see how the use of modern genomics technologies is going to be of direct benefit for patient care. It is exciting that we have shown that the genetic basis of a rare bleeding disorder can be discovered with relative ease", said Professor Willem Ouwehand, who heads a NHS Blood and Transplant research team on platelet biology at both the Wellcome Trust Sanger Institute and the University of Cambridge. "This study is one such example and it gives us confidence to achieve the same for a large number of other rare inherited platelet bleeding disorders. It is now important that we use this discovery to improve patient care in the NHS and beyond."

The team's identification of the NBEAL2 gene was confirmed by functional studies in zebrafish. Fish also have platelets named thrombocytes, and switching off the NBEAL2 gene in fish caused a complete absence of these cells which resulted in nearly half of the fish suffering spontaneous bleeds similar to patients with the disorder.

It is hoped that this gene identification will make it simpler to diagnose future cases of Grey Platelet Syndrome with a simple DNA test. This new test is now being developed with researchers at the NHS Blood and Transplant Centre at the Addenbrooke's Biomedical campus in Cambridge as part of the international ThromboGenomics initiative.

The scientists also observed that other members from the same family of BEACH proteins are implicated in other rare inherited disorders. Their findings showed that LYST protein did not function well in Chediak-Higashi syndrome, another rare but severe disorder paralysing the immune system but also causing a mild platelet bleeding disorder. As a result, a picture is emerging that BEACH proteins are essential in the way granules in blood cells and brain cells are formed or retained showing that in platelets the BEACH proteins are essential for both alpha and dense granules.

"Our discovery that another member of the family of BEACH proteins is underlying a rare but severe granule disorder in platelets firmly nails down the important role of this class of proteins in granule biology," said Cornelis Albers, a British Heart Foundation research fellow at the Sanger Institute and the University of Cambridge. "The reasons why the platelets of patients with Grey Platelet Syndrome are grey is because they lack alpha granules. The alpha granules carry the cargo of proteins that induce vessel wall repair and also form the platelet plug.

"A better understanding of how these granules are formed and how their timely release by the platelet is coordinated at the molecular level may one day underpin the development of a new class of safer anti-platelet drugs for use in patients with heart attacks and stroke. It has been a fascinating journey to identify a new and important pathway by combining the rapid advances in sequencing technology with computational analysis."

The French collaboration leader, Dr Paquita Nurden, set up the Network for Rare Platelet Disorders at the Laboratoire d'Hématologie, Hopital Xavier Arnozan close to Bordeaux. Their team made the Heruclian effort to find the French families affected by this rare disorder.

"We have worked for years to identify the families across France that suffer from rare platelet disorders and my group of scientists have used powerful microscopes to determine what was wrong with the platelets from patients with Grey Platelet Syndrome. Researchers across the world discovered in the 1980s that something was wrong with the alpha granules because they were lacking in most of the cases," said Dr Nurden, an international expert in platelet biology. "The gene, however, remained elusive for another 30 years, and it is great how our joint working has discovered the causative gene very quickly."

Notes to Editors
Publication details
Exome sequencing identifies NBEAL2 as the causative gene for gray platelet syndrome.

Albers CA, Cvejic A, Favier R, Bouwmans EE, Alessi MC, Bertone P, Jordan G, Kettleborough RN, Kiddle G, Kostadima M, Read RJ, Sipos B, Sivapalaratnam S, Smethurst PA, Stephens J, Voss K, Nurden A, Rendon A, Nurden P and Ouwehand WH

Nature genetics 2011

PUBMED: 21765411; DOI: 10.1038/ng.885

Funding
The research team in Cambridge is supported by the British Heart Foundation, the European Commission, the National Institute for Health Research, NHS Blood and Transplant and the Wellcome Trust.
Participating Centres
Bordeaux is the coordinating centre for French National Reference Network for inherited platelet diseases, identified by the French Health Ministry. Through this network it became possible to precise the epidemiology of these diseases and identify new groups of patients with similarities to increase the chance to define the mutations responsible for the disease.
NHS Blood and Transplant (NHSBT)
Professor Ouwehand is also a consultant Haematologist for NHS Blood and Transplant (NHSBT). NHSBT collects blood and platelets from non-remunerated volunteer donors. Every day about 10,000 units of blood are needed by the NHS and 1100 platelet concentrates. For the latter about 600 donors attend a special clinic at which platelets are harvested from the blood of the donor by a process called apheresis.
The Wellcome Trust Sanger Institute
The Wellcome Trust Sanger Institute, which receives the majority of its funding from the Wellcome Trust, was founded in 1992. The Institute is responsible for the completion of the sequence of approximately one-third of the human genome as well as genomes of model organisms and more than 90 pathogen genomes. In October 2006, new funding was awarded by the Wellcome Trust to exploit the wealth of genome data now available to answer important questions about health and disease.
Websites
http://www.sanger.ac.uk/
The Wellcome Trust
The Wellcome Trust is a global charitable foundation dedicated to achieving extraordinary improvements in human and animal health. We support the brightest minds in biomedical research and the medical humanities. Our breadth of support includes public engagement, education and the application of research to improve health. We are independent of both political and commercial interests.
Website
http://www.wellcome.ac.uk

Don Powell | EurekAlert!
Further information:
http://www.sanger.ac.uk

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>