Which of the following can be used as a cure for ADA deficiency?

All of these.

a-Gene isolate from marrow cells producing ADA is introduced into cells at early embryonic stages.

b-Enzyme replacement therapy by injecting functional ADA enzyme.

c-Gene therapy by introducing functional ADA gene into the lymphocytes followed by their infusion into the patient.

d-All of these is the correct option .

In some children ADA deficiency can be cured by bone marrow transplantation; in others it can be treated by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But the problem with both of these approaches that they are not completely curative. As a first step towards gene therapy, lymphocytes from the blood of the patient are grown in a culture outside the body. A functional ADA cDNA (using a retroviral vector) is then introduced into these lymphocytes, which are subsequently returned to the patient.This is because the cells are not immortal and a periodic infusion is required. The lymphocytes are short lived with their average lifespan between a week to some months. However, as these cells are not immortal, the patient requires periodic infusion of such genetically engineered lymphocytes. However, if the gene isolate from marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure.