Happy New Year!
A six month old baby is referred to you because of profound anemia of 4.5 g/dL. He has a snub nose, wide set eyes, a thick upper lip, and an intelligent expression. Looking at the records, you note a progressive normochromic and macrocytic anemia. The WBC and platelet counts are normal. The patient's reticulocytes are markedly decreased. There is increased Hgb F. The bone marrow shows normal cellularity but very few erythrocyte precursors. Red cell adenosine deaminase activity is increased. There is a positive family history for this disease.
Challenge: What's going on?