Question

Mention two disadvantages of enzyme - replacement therapy to treat ADA( adenosine deaminase defficiency.

Answer 1

ADA is caused due to deletion of the gene for adenosine deaminase.
in some children it is cause by-
1) Bone marrow Transplantation
2) Enzyme replacement therapy
In enzyme replacement therapy functional ADA is given to the patient by injection
1) Lymphocyte from the blood of the patient are given in a culture outsied the body
2) A functional ADA cDNA (using a retroviral vector) is introduced into the lymphocyte which are Returned to the patient.
3) These cells are not immortal, the plant require them periodic infusion.
4) If the gene isolate from marrow cells producing ADA is introduced into the cells at early embryonic stage, it could be permanent cure.
Two Disadvantages of this procedure
a) These cells do not always remain alive.
b) Patient required periodic infusion of genetically engineered lymphocyte