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

Options

A. Periodic infusion of genetically engineered lymphocytes having functional ADA cDNA.
B. Administering adenosine deaminase activators
C. Introducing bone marrow cells producing ADA into cells at early embryonic stages
D. Enzyme replacement therapy

Answer

A

Explanation

Severe combined immunodeficiency (SCID) caused by adenosime deaminase deficiency (ADA) is the firstgenetic disorder to be treated with gene therapy. T - Cell directed gene transfer was usefull in the treatment of ADA - SCID, whereast the retroviral - mediated gene transfer to haematopoietic stem cells was insufficient for achievement of clinical benefits.