An international research consortium with the participation of the German Center for Neurodegenerative Diseases (DZNE) and the Bonn University Hospital has identified 11 previously unknown genetic risk factors for Alzheimer's disease.
The genome of over 25,000 patients as well as more than 48,000 healthy controls was analyzed to this end. The results have been published in the scientific journal “Nature Genetics”.
Alzheimer’s disease is a common cause of dementia. It is triggered by the death of brain cells and occurs in two variants: The so-called familial variant is relatively rare. It is caused by certain mutations in the genome and usually manifests itself already before the age of 65. However, more than 90 percent of the cases occur at an older age. The exact causes of this “sporadic” form of the disease are enigmatic. However, it is known that a disease may be favored by genetic traits, even though it may not necessarily be triggered by it.
So far, 11 such risk factors were known. A further 11 have now been identified by a team of researchers from the US and Europe. For this several universities and research institutions collaborated within the framework of the “International Genomics of Alzheimer's Project” (IGAP).
Large amounts of data
“Such an endeavor is enormously complex and requires the cooperation of many partners. We in particular contributed clinical data. This included anonymous genetic data of about one thousand patients that are diagnosed with Alzheimer’s disease,” says Dr. Alfredo Ramirez, who is a researcher at the Department of Psychiatry and Psychotherapy of Bonn University Hospital.
The memory clinic played an important role, explains Professor Frank Jessen, who is Deputy Director of the Department of Psychiatry and Psychotherapy and also a researcher affiliated to the DZNE: “Longtime preparations are needed for such a study. On the basis of our memory clinic we have been in touch with people diagnosed with memory disorders for many years. Through this we have been able to build up an extensive repository of genetic data from patients. We made this data available for the study.”
“In the case of such genetic studies, it is ultimately a matter of comparing the genomes of patients and controls,” explains Dr. Tim Becker from the Bonn site of the DZNE. Within the framework of the now published study he focused in particular on the analysis of genetic data. “We searched for genetic traits that are prevalent in persons that have been diagnosed with the disease. In order to do so, genetic data from many people has to be compared. This is the only way to obtain meaningful results and to distinguish random signals from real findings.”
Important contributions also came from the Institute of Human Genetics of the Bonn University Hospital. “We genotyped samples of DNA. This is very similar to doing genetic fingerprinting,” says Professor Markus Nöthen, head of the Institute.
Screening the genome
The IGAP consortium studied the genome of a total of 74,046 people. Of these, more than 25,000 were diagnosed with Alzheimer’s disease, the others were controls. High performance computing assisted in the analysis of the huge amount of data.
Pivotal to the research were so-called genome-wide association studies (GWAS). The genome, with its billions of building blocks, was thereby not fully cataloged, but instead only examined at relevant positions. This type of screening saves time and money, while at the same time providing a good coverage. The researchers examined about seven million positions.
“We identified eleven positions in the human genome that were previously largely ignored. However, if certain alterations are present there, the probability of developing Alzheimer’s increases,” says Becker. “Yet, this increased risk does not necessarily lead to disease.”
So far the researchers do not yet know in detail what role the affected regions play. “Some of these genes are related to Amyloid-beta and tau proteins that are known to be relevant for the Alzheimer’s disease. With regard to the other critical regions, we can not say with certainty what role they play”, says Ramirez. “We assume that they have an effect, for example, on nervous connections and on transport processes occurring inside the nerve cells. In addition, the immune system seems to be involved. As a next step, it will be important to investigate this in more detail.”Original publication
Dr. Marcus Neitzert | idw
Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy