Explain how ADA deficiency can be corrected ?

Explanation

The first clinical gene therapy was given in 1990 to a individual with adenosine deaminase (ADA) deficiency . ADA deficieny or SCID (Servere combined immunodeficiency) is an autosomal recessive metabolic disorder. It is caused by the deletion or dysfunction of the gene coding for ADA enzyme. In these patients, the non-functioning T-Lymphocytes cannot elicit immune responses against invading pathogens. The right approach for SCID treatment would be to give the patient a functioning ADA which breaks down toxic biological products.
Treatments :
(i) In some children ADA deficiency could be curved by bone marrow transplantation, where defective immune cells could be replaced with healthy immune cells from a donor .
(ii) In some patients it can be treated by enzyme replacement therapy , in which functional ADA is injected into the patient.
(iii) During gene therapy, lymphocytes from the blood of he patient are removed and gentically engineered by inserting the gene for ADA enzyme .
(iv) The disease can be cured permanently. If the gene for ADA isolated from bene marrow cells are introduced into the cells of the early embroyonic stages.