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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Adenosine deaminase deficiency is seen in the following:
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The correct answer is  The most common cause of autosomal recessive severe combined immunodeficiency(SCID) is the deficiency of enzyme adenosine deaminase (ADA)Defect lies in lymphoid stem cells, resulting in failure of both T and B cellsDeficiency of ADA leads to accumulation of deoxyadenosine & its derivatives, which are toxic to immature lymphocytes, especially those of T lineage, and this may account for the marked decrease in T lymphocyte number in severe cases(ref: Harrison's 18/e p2700)