Gene therapy - patched genome

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

More posts by Christiane Fux All content is checked by medical journalists.

In theory, errors in the genome can already be remedied in a targeted manner today. But gene therapy is still in its infancy - the risks are high.

Congenital or acquired genetic malfunctions are the cause of many ailments - from hereditary diseases to cancer. Gene therapy usually aims to compensate for or correct errors in the genetic make-up.

Replacement Therapy - Fixed Code

The supreme discipline of gene therapy is probably substitution therapy. The aim is to exchange diseased genes in the body for healthy ones. In the optimal case, this type of therapy only needs to be applied once.

For substitution therapy, medical professionals have to channel therapeutic genes into the patient's body cells. Viruses that have perfected such a process for their own reproduction are usually used as transport vehicles. First, the virus is defused so that it does not make the patient sick. This removes all genes of the virus that could be harmful to humans. But that does not yet work perfectly: Studies have repeatedly shown very critical courses of the disease. Scientists are therefore working on methods in which the viruses are replaced by more compatible artificial transporters (vectors).

The transporters can be injected into the blood or tissue (in vivo), or the doctors take cells from the patient, which are then "infected" with the healthy genes in the laboratory and then replanted (ex vivo). Sometimes, as in the case of cystic fibrosis, success has also been achieved with breath spray. However, the effects only lasted about 30 days.

Cystic fibrosis is a monogenic disease in which only a single gene is defective. The researchers are currently placing particular hope in their healing. So far, however, the method is a dream of the future for most people with genes. Gene therapy is still in its infancy and involves high risks.

In Germany, therefore, life-threatening patients, mostly children for whom there are no other healing methods, are given preference to be treated with gene therapy. The best-known examples of this application are monogenic immune diseases in which only a single gene is defective, in particular diseases of the immune system.

With these, a bone marrow donation is often the only prospect of a cure. But finding a suitable donor often takes too long and, if left untreated, patients die very young. As part of gene therapy, bone marrow cells are equipped with the appropriate gene and brought back into the patient's body. This has already been successful in individual cases.

Addition therapy - strength training for genes

Addition therapy is about strengthening certain gene functions. An example of this is the attempt to smuggle genes into the immune cells that strengthen the defense against cancer. This form of gene therapy has so far only been used very rarely because its risks have not been adequately researched.

Suppression Therapy - Cut Out Troublemakers

The goal of suppression therapy is exactly the opposite: The aim here is to specifically suppress unhealthy gene activity. One possible area of application would be the therapy of HIV-infected people, which uses gene therapy to stop the spread of the fours in the blood.