Genes play an important role in human health and genes that don't work properly can cause disease. Sometimes the whole or part of a gene is defective or missing from birth, or a gene can change or mutate during adult life. Any of these variations can disrupt how proteins are made, which can contribute to health problems or diseases.

Gene therapy is used to correct defective genes in order to cure a disease or help the body better fight disease. It's the introduction, removal or change in genetic material—specifically DNA or RNA—into the cells of a patient with the aim to restore normal function, to treat a specific disease.

Realizing the potential of gene therapy

The majority of diseases treated with gene therapy are inherited genetic diseases, but gene therapy is also used to treat certain cancers and viral infections. So far scientists have successfully used gene therapy to slow the progression and improve symptoms of rare and often life-threatening disorders and holds promise for treating a wide range of diseases.

Gene therapy is a promising treatment option for a number of diseases and the general strategy of gene therapy is relatively straightforward.

There are several approaches to gene therapy, in short:

• Replacing a mutated or defective gene that causes disease with a healthy copy of the gene may help treat certain diseases.
• Fixing mutated genes that is functioning improperly causing disease. This is done either by turning the mutated genes off so that they no longer promote disease, or by introducing or turning on healthy genes that help prevent disease so that they can inhibit the disease.
• Making diseased cells more evident to the immune system. In some cases, your immune system doesn't attack diseased cells because it doesn't recognize them as intruders. Doctors could use gene therapy to train your immune system to recognize the cells that are a threat.