Question

The genetic defect adenosine deaminase (ADA) deficiency may be cured permanently by

(1) enzyme replacement therapy.

(2) periodic infusion of genetically engineered lymphocytes having functional ADA cDNA.

(3) administering adenosine deaminase activators.

(4) introducing bone marrow cells producing ADA into cells at early embryonic stages.

Answer 1

The individual suffering from genetic defect adenosine deaminase (ADA) deficiency can be cured by transplantation of bone marrow cells. The first step involves the extraction of lymphocyte from the patient’ bone marrow. Then, a functional gene for ADA is introduced into lymphocytes with the help of retrovirus. These treated lymphocytes containing ADA gene are then introduced into the patient’ bone marrow. Thus, the gene gets activated producing functional T-lymphocytes and activating the patient’* immune system.

Hence, the correct option is (4).