the first clinical gene therapy that was ultimately unsuccessful was done for the treatment of severe immune system deficiency.
the first clinical gene therapy that was ultimately unsuccessful was done for the treatment of severe immune system deficiency.
the first clinical gene therapy that was ultimately unsuccessful was done for the treatment of?
severe immune system deficiency
Na
Na
gene therapy is another treatment option which is available only for clinical trials. x-linked scid is a monogenic disorder, the il2rg gene is mutated, so gene therapy will replace this mutated gene with a normal one. this will result in a normal functioning gamma chain protein of the interleukin receptor. in order to transfer a functional gene into the target cell, viral or non-viral vectors can be employed. viral vectors, such as the retrovirus, that incorporate the gene into the genome result in long-term effects. this, coupled with the bone marrow stem cells, has been successful in treating individuals with x-scid. in one particular trial by cavazzana-calvo et al., ten children were treated with gene therapy at infancy for x-scid. nine of the ten were cured of x-scid. however, about three years after treatment, two of the children developed t-cell leukemia due to insertion of the il2rg gene near the lmo2 gene and thereby activating the lmo2 gene (a known oncogene). a third child developed leukemia within two years of that study being published, likely as a direct result of the therapy. this condition is known as insertional mutagenesis, where the random insertion of a gene interferes with the tumor suppressor gene or stimulates an oncogene. there is currently no approved gene therapy on the market, but there are many clinical trials into which x-scid patients may enroll. therefore, research in the field of gene therapy today and in the future is needed to avoid the occurrence of leukemia. in particular, research into the use of insulator and suicide genes is warranted as this may prevent cancer from developing. the insulator gene inhibits the activation of adjacent genes. on the other hand, the suicide gene is stimulated when a tumour begins to form, and this will result in the deactivation of the therapeutic gene. moreover, the use of restriction enzymes such as the zinc-finger nuclease (zfn) is being studied. the zfn allows the researcher to choose the site of gene integration. vector safety is important in the field of gene therapy, hence vectors that self-inactivate the promoter and enhancer (sin) and adenoviruses that creates no immune response are prominent areas of research for vector biologists.
x-linked severe combined immunodeficiency