Who was the first patient to b e treated with gene therapy? Why was the given treatment recurrent in nature?

Explanation

Gene therepy is a collection of methods that allows the correction of gene defects diagnosed in a child or embryo correction of a genetic defect involves the dlivery of a normal gene into the individual or embryo to take over the function of and com pensate for the non-functional gene.
The first clinical gene therepy was given in 1990 to a 4 yrs old girl with Adenosine Deaminase (ADA) deficiency.
ADA deficiency is caused due to the deletion of gene for Adenosine Deaminase. it can be cured by bone marrow trasnplantation or by enzyme replacement therapy. in both the approaches. it is not completelyy curable.
It may recurrent in nature because in the process of gen e therapy, lymphocytes used are found to be mortal in nature and the patient requires periodic infusion of such genetically engineered lymphocytes.
For permanent cure, gene isolated from the bone marrow. cells producing ADA is introduced into the cells at early embryonic statges.