HEALING


Altered Genes and Complex Diseases

When a body cell needs a new protein, a corresponding blueprint first has to be read. The information thereto is stored in the corresponding genes.
Occasionally the blueprint is altered due to external influences. That may imply small changes in which only a single gene letter has been exchanged or whole segments of the construction guidance may be missing.
The consequences of such changes: the protein may be either not produced at all or it may be defectively assembled, so that it is no longer functioning properly.
Often there are safety precautions with which the human body can "iron out" the error. But the error in a single protein does not necessarily lead to an illness. The illness develops when several genes are altered and this is perhaps accompanied by damaging environmental influences (e.g. radiation, etc.) or certain lifestyle habits (e.g. smoking, unhealthy diet, etc.).




In medical terminology such diseases are therefore called "complex diseases". Complex because there may be five or ten genes that play a role in the disease - plus environment factors and behavior, so there is not only one cause. Cancer, allergies, high blood pressure and Alzheimer’s – all of these well-known afflictions belong to that group.
In addition,  a seemingly similar disease can be triggeredin different people by different combinations of genetic mutations and environmental factors. For instance, in one person an unhealthy diet and a gene defect can lead to hypertension, whereas in another hypertension patient perhaps quite another gene and everyday stress trigger the disease. That is why it is so difficult to find out what is causing this disease. That is probably also the reason why until now only twenty percent of the approximately 30,000 known diseases can be treated with drugs. Only when the cause of a disease is known is it possible to develop a tailor-made therapy.  If the cause is unknown, the development of corresponding medications has to be done by trial and error, a method that frequently is accompanied by undesirable side effects.
With the aid of systematic genome research it is now possible to find new points of attack for drugs. To begin with, researchers are comparing diseased and healthy tissues and are searching for proteins that function differently or are present in greater quantities in an ill patient compared to a healthy individual. Then they attempt to construct an agent that activates or blocks the altered protein.

The insight of genome researchers can benefit patients in another way as well. Perhaps it will soon be possible to assess whether and in what dosage a drug will be effective in a patient.
Not all drugs have the same effect in all patients. The effectiveness of a drug also depends on the genetic constitution of the patient. Not all patients react to a drug in the same way. For instance, in many patients even the standard dosage of a common drug leads to severe complications. The spectrum of side effects ranges from nausea and allergic reactions to cardiac insufficiency and increased risk for cancer.
The reasons for such side effects are genetic variations in the proteins of each patient, for example in the proteins which are responsible for the resorption of drugs. Some of these proteins are altered to such an extent that they do not or only very slowly eliminate drugs from the body.
In some patients a drug has no effect at all – even though in other patients good achievements in recovery can be obtained with the same drug. Most drugs function so that they have to dock to a damaged protein to block its dangerous activity. But sometimes right at the docking site the protein is genetically altered in such a way that the drug can no longer adsorb there, thus remaining without any effect.
Through genome research it would be possible to identify such patients already in advance. Then the doctors could reduce the dosage of a drug early enough or introduce another therapy.
   
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