Read the following statements regarding Adenosine deaminase (ADA) deficiency and its treatments: (A) ADA deficiency is caused by the deletion of the gene for adenosine deaminase. (B) Enzyme replacement therapy provides a permanent cure for this disease. (C) Bone marrow transplantation is a completely curative approach for all ADA patients. (D) Introducing the functional ADA gene into cells at early embryonic stages c

Step-by-step solution

Statement (A) is correct as ADA deficiency is caused due to the deletion of the gene for adenosine deaminase. Statements (B) and (C) are incorrect. While ADA deficiency can be treated by bone marrow transplantation or enzyme replacement therapy (where functional ADA is given to the patient by injection), neither of these approaches is completely curative. Statement (D) is correct. If the gene isolated from marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure. T