question_answer

When a patient with defective ADA was treated, which of the following steps was performed for gene therapy?

(i) Lymphocytes were obtained from the patients.

(ii) Lymphocytes are transferred to culture dishes.

(iii) Lymphocytes were transfected with normal ADA genes.

(iv) The transfected cells are returned to the patients.

A) All of the above

B) (iii) and (iv)

C) Only (iv)

D) SCID cannot be treated