Question

Why is the introduction of genetically engineered lymphocytes into a ada deficiency patient not a permanent cure?

Answer 1

Lymphocytes are not immortal / short lived, hence patient requires periodic infusion of such genetically engineered lymphocytes, however if a gene producing ADA is isolated from marrow cells, and introduced into the cells at early embryonic stages it could be a permanent cure.

Detailed Answer:

In case of ADA deficient patients, lymphocytes from their blood are grown in a culture. A functional ADA, cDNA (using a retroviral vector) is then introduced into the lymphocytes. These lymphocytes are subsequently returned to the patients. However, as these cells are not immortal, the patient requires periodic infusion. Thus, infusion of genetically engineered lymphocytes is not a permanent cure.

A permanent cure for ADA deficiency is to introduce genes isolated from marrow cells that produce ADA into cells at early embryonic stag

Answer 2

ADA (Adenosine Deaminase)  

Explanation:

1. The Genetically engineered not a permanent cure of lymphocytes.
2. The bone marrow of lymphocytes contained a functional ADA gene.
3. The genetically engineered lymphocytes injected into the patient should outgrow the "natural" lymphocytes.
4. The ADA different cells to not divide as a fact as those with active enzymes.
5. Deficiency of ADA is the two chromosomal recessive traits that caused the immune system is dysfunction.
6. The stems cells of gene therapy would get around this problem.
7. The  injected lymphocytes are mature and have limited life spam