Beta-thalassemia major, also known as Cooley's anemia, has inherited two genes for beta thalassemia without...

Beta-thalassemia major, also known as Cooley's anemia, has inherited two genes for beta thalassemia without a normal beta-chain gene. This disease is assoicated with a marked deficiency in beta chain production and in the production of normal Hb A. These patients exhibit increased amounts of iron due to the mutliple transfusions that keep them alive. There is also a striking increase in hemoglobin F and an elevation in hemoglobin A2.

Hematology

A 5-year-old African American child with hepato-splenomegaly and skeletal abnormalities has the following lab results:

WBC = 4,800/cu.mm

20 NRBC/100 WBC

RBC = 2.70 X 106

HGB = 6.2 g/dL

Many target cells

Marked hypochromasia, anisocytosis & poikilocytosis

Serum Iron = 200 µg/dL (elevated)

Sickle Solubility = negative

Hemoglobin F = elevated

What is the PROBABLE cause of these findings?