Alzheimer experts are an epochal step further in the investigation of the illness
- Written by Alexander Lorenz
- Parent Category: Medicine
- Created: 11 September 2009
In the famous magazine "Nature Genetics" from the 06.09.2009 produced the Alzheimer expert who will take over from the chair 01.01.2010 of psychiatry of the Goethe's university (press conference for the new appeal follows), the proof of the fact that the outbreak of the illness can be caused genetically. Up to now, nevertheless, only four genes which are involved in the genetically complicated illness were known. Now two big international research teams have discovered three new risk genes which serve to become forgetful irreversible at the age. Within the scope of the up to now worldwide biggest Alzheimer genetics study with more than 16,000 examined people, the experts made a find.
Three new risk genes
On the past week-end the scientists presented three anew discovered risk genes which are involved in the origin of the Alzheimer illness. "Our results could lead to quite new ways of treatment with the Alzheimer illness", said Prof. Julie William of Cardiff university in the press conference of "Nature Genetics". Professor Michael Owen, her colleague in Cardiff university, added that in future - if other risk genes are known for the Alzheimer illness - maybe a genetic test can be used as a criterion for an Alzheimer diagnosis or for a wide Screening.
Till this day there are for Alzheimer patients merely drugs which influence the illness course symptomatically and delay only clinically in approx. one year. There are not the therapies which delay the loss of memory substantially or heal even up to now. "With our method to look for risk genes we have done an epochal step", stresses Prof. Hampel. For the first time the researchers could analyse big patient's groups and control groups genetically, because to examine genetically "complicated illnesses like Alzheimer, asthma or diabetes, is first since the deciphering of the human genome eight years ago possibly" thus Prof. Hampel.
New explanation attempts about the origin
Now the discovery should deliver new explanation attempts about the origin of the Alzheimer illness. Already during the last years the experts could analyse the complicated mechanisms of cerebral processes better and better. The first important tips gave also mutant genes which contribute substantially to the origin of the early form of the Alzheimer illness. Nevertheless, changes in the genes appear as very rare, only about three percent of the Alzheimer cases are to be explained with it. Often the members of the family who carry one of these morbidly mutant genes become unusually early obliviously - already from the 30th year. Nevertheless, as a rule the Alzheimer illness appears only from the 60th year. This kind of the Alzheimer dementia concerns more than 95% of the patients. The risk gene most important up to now for this late and more frequent form of the illness is the Apolipoprotein E discovered 16 years ago (ApoE).
Both research groups under the direction of Williams and Philippe Amouyel of the Pasteur institute in Lille have recognised the ApoE gene as the clearest risk gene. In addition, they discovered a related gene, called Apolipoprotein J." Among the rest, the Apolipoproteine deal something with the cholesterol metabolism. Maybe we can soon explain more exactly, why, for example, people with low cholesterol values possibly have a lower risk to fall ill with Alzheimer. Epidemiological studies have already shown this" thus professor Hampel. Both Apolipoproteine presumably have also a protective function for the brain. They remove the injurious Beta-Amyloid, besides, ApoJ damps inflammations. Up to now the researchers assumed from the fact that inflammations are a result of the illness in the brain of Alzheimer patients. Nevertheless, results of the research show that inflammations could be the first illness step in the brain. Now thus an explanation would be thought of the fact that people, the in the long term certain anti-inflammatory preparations took, fall ill more seldom with Alzheimer.
Also with the second discovered risk gene with name CR1 the researchers suppose that it is involved to put out of action the toxic Beta-Amyloid.
However, the third gene with the long name PICALM has an influence on the synapses. In the brains of Alzheimer patients the number of these contact places about which nerves communicate with each other is reduced. If nerve cells cannot step at these contact places together any more enough in connection, the commemorative achievement sinks.