Probably, applied genetics' most impacts on society are as a result of genetic tests. In general, genetic tests seek to detect some feature of a person's genetic constitution. This feature can be a disease causing mutation or a marker DNA sequence used to detect presence of another gene. Obviously these procedures used for testing the status of DNA, RNA or chromosomes are included in genetic tests. What is more it is possible to include some protein based tests and classical medical examinations when they aim to detect inheritance of a trait. Genetic tests have been divided into four categories in this text, and they will be examined in greater detail later. These categories are: Prenatal tests that are applied on fetuses during pregnancy. Neonatal screening just after birth and career screening of marrying couples. Testing for serious late-onset disease before the symptoms occur. Testing to assess the probability of developing complex disease.
There are a couple of considerations about genetic tests: 1. First of all, the tests should be reliable. When a positive or a negative result is obtained, we should be confident in that result with a confidence approaching 100%. To achieve such a high accuracy is not as easy as it may at first appear to be. Meiotic recombinations that always occur take place during gamete generation, may separate a disease-associated gene and a marker DNA sequence which is used to detect mutated genes. False positive or negative results could be obtained. In addition, genetic tests look for the most common mutations that cause the disease. For example, a test would detect CFTR?F508 (Cystic Fibrosis Transmembrane Receptor) mutation, however it is not possible to detect infinite number of other mutations. Therefore, a genetic test can give such results so that the physician is convinced that his patient is normal while he is affected by an undetectable mutation. New tests are continuously being developed. Doctors and genetic counselors who will use these tests in the future, should be well informed about newly emerging tests.
2. Extremely accurate genetic tests can only be developed by thorough experimentation on human subjects. Although there is generally no physiological risk in experimenting a person, the subjects should be informed that the applied test is not entirely reliable and in experimentation state. Informing subjects of experimentation is an obligation set by the Nuremberg Code. Just after World War II it was discovered that unethical experiments had been performed on humans who were kept in concentration camps of Nazi Germany. This situation was discovered in Nuremberg Trials, and ethical and legal standards for medical experimentation were set then. Research and common medical procedures are distinct concepts. If a genetic test's validity has been proven by extensive research and the test being used as a routine medical procedure to diagnose patients, it is no more considered as experimental and is not covered by the Nuremberg Code. Nevertheless, the patient should be well informed and his consent should be taken even before applying a routine test. The subject of the test should fully understand the nature of the test and the consequences that may arise from it. The subject of the test should be fully aware of the nature of the test and the consequences caused by the test. Therefore, a professional counselor is needed to psychologically counsel and inform the subjects both before and after the test is taken. Sometimes, the person taking the test cannot give an informed consent when it is a small child or mentally retarded person. In this case, it is still required to take consent of the parents or legal guardians. The tests should only be applied for vital medical reasons. For example, it is not very ethical to test a young girl for a sex linked genetic disease. Because it is intensely related with the future life of the...
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