This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Adenosine deaminase deficiency is seen in the following - 
Select and explain. 
A. Common variable immunodeficiency, B. Severe combined immunodeficiency, C. Chronic granulomatous disease, D. Nezelof syndrome
B: Severe combined immunodeficiency
Answer: B: Severe combined immunodeficiency 
Explanation: Severe combined immunodeficiencies include syndrome with severe deficiency of both humoral and cell mediated response. Adenosine deaminase deficiency is a distinct pattern of SCID. - ADA catalyses the conversion of adenosine to inosine in the purine metabolic pathway. This condition is associated with chondrocyte abnormalities. Reference : Anathanarayan & paniker's 9th edition, pg no:174,175 <\p>