Adenosine deaminase deficiency
- Adenosine deaminase deficiency
- Converts adenosine to inosine in purine salvage pathway.
- Excess ATP, dATP in nucleotide pool = imbalance (feedback inhibition of ribonucleotide reductase, preventing DNA synthesis), so decreased lymphocyte count
- major cause of SCID, severe combined immunodeficiency dz, e.g. “bubble boy”
Adenosine deaminase deficiency is seen in the following:
- Common variable immunodeficiency.
- Severe combined immunodeficiency
- Chronic granulomatous disease
- Nezelof syndrome