Explanation

SCID is caused due to defect in the genes for the enzyme adenosine deaminase. In some children, ADA deficiency can be cured by bone marrow transplantation. However, in others it can be treated by the enzyme replacement therapy in which functional ADA is given to patient by injection. But in both approaches, the patients by are not completely cured. For permanent cure, genes isolated from the bone marrow cells producing ADA at early embryonic stage can be a possible cure