The preparation for the examination | The genetic examination

The preparation for the examination

The preparation for the examination includes an indication – it must be clearly evident why one wants to do a genetic examination. In addition, the patient should be informed about possible effects and changes in his or her life if the test result is positive. After a certain period of consideration, the examination can be carried out, but the patient must give his or her written consent, since there is a genetic diagnostics law in Germany that strictly regulates DNA analyses.

The procedure

Depending on which test is performed, either blood must be drawn from the patient or saliva can be extracted from the oral mucosa with a cotton swab. In some tests hair can also be collected. Afterwards the material obtained is sent to a laboratory.

There the DNA is extracted from the cell nucleus. The gene section to be examined is amplified (so-called polymerase chain reaction) and molecular-genetically examined. After the necessary analyses, the results are reported to the treating physician, who should discuss them in detail with you.

The Evaluation

After the molecular genetic examinations, the results are compiled. The guidelines are databases that were previously created in large studies. The result with is compared with this database and is usually very reliable.

However, a positive result does not mean 100% that one is ill. Many mutations have no effect because they are neutral mutations. In addition, the genes have a different penetrance. Simplified explained it means that the expression of genes is individually different. The result should definitely be explained to you again by the treating physician, since this is a more complex topic.

The risks

Postnatal diagnostics is actually hardly risky. As a rule, a simple blood sample or saliva is sufficient for the analysis. However, life may change completely after a positive test result.

Some hereditary diseases are unfortunately incurable and can be a psychological burden. Social isolation is also conceivable. For this reason, the patient should be informed before the test is performed so that he or she is aware of any consequences.

The risk of prenatal diagnostics varies and has more risks depending on the test procedure. An amniocentesis or a biopsy of the placenta may result in bleeding or loss of amniotic fluid. The most feared complication is miscarriage, which occurs in only 0.5% of cases.