A permanent cure for ADA deficiency could be:

Which kind of therapy was given in 1990 to a four-year-old girl with Adenosine Deaminase (ADA) deficiency?

(1) Gene therapy 

(2) Chemotherapy

(3) Immunotherapy

(4) Radiation therapy

The genetic defect-Adenosine Deaminase (ADA) deficiency may be cured permanently by

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

(2) administering adenosine deaminase activators

(3) introducing bone marrow genes producing ADA into cells at early embryonic stages

(4) enzyme replacement therapy

An example of gene therapy is 

(1) production of injectable hepatitis B vaccine 

(2) production of vaccines in food crops like potatoes which can be eaten

(3) introduction of gene for adenosine deaminase in persons suffering from Severe Combined Immuno-deficiency (SCID)

(4) production of test tube babies by artificial insemination and implantation of fertilized eggs.

Adenosine deaminase (ADA deficiency) could be permanently cure, if the gene isolated from marrow cells producing ADA is introduced into cell at

(1) early embryonic stages

(2) Late embryonic stages

(3) early childhood

(4) None of the above