Gene therapy

According to hematologist Arthur Nienhuis, former president of the American Society of Gene Therapy, gene therapy:

....is the addition of new genes to a patient’s cells to replace missing or malfunctioning genes. Researchers typically use a virus to carry the genetic cargo into cells, because that is what viruses evolved to do with their own genetic material.

In 2008, Arthur Nienhuis reported that gene therapy cured 90% of 30 patients with a genetic disorder called severe combined immunodeficiency disease (SCID), children who cannot ward off routine infections and die in childhood (bubble-boys). The gene therapists inserted the therapeutic gene in the SCID patients using a category of virus known as retroviruses, which have an easy time inserting their genes among the DNA of the patient. The method has the possibility the retrovirus will insert its genes where it can adversely affect other genes and cause leukemia. Fortunately the risk seems small, and the leukemia mostly curable. With larger numbers of patients treated and followed throughout their life, gene therapist can assess the full potential for cure and for adverse effects in SCID.

Nienhuis also pointed out that gene therapists have targeted a wide range of medical conditions for gene therapy application:

Cancer, genetic disorders, immunologic disorders such as graft -vs.-host disease, neurodegenerative disorders, and infectious diseases, including AIDS, have all become targets for gene therapy applications.

Some target specifically diseases resulting from genetically defective bone marrow cells, which provide the for red blood cells and other elements of blood and the cells that maintain bone as a healthy organ. They do bench gene therapy by inserting genes in immature bone marrow cells harvested from the patient, then replace the genetically modified immature bone marrow cells so that they can ultimately replace all the defective cells in the bone.