ADA is caused by?
Answer & explanation
Correct answer: option 2
The first clinical gene therapy was given in 1990 to a 4-year old girl
with adenosine deaminase (ADA) deficiency. This enzyme is crucial for
the immune system to function. The disorder is caused due to the deletion
of the gene for adenosine deaminase. 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.