11-06-2006, 10:47 PM
A 17-year-old male presents with passage of dark
urine. He has had multiple bacterial infections over several
years and has a history of venous thromboses, including
portal vein thrombosis in the previous year. A CBC shows
a hemoglobin concentration of 9.8 g/dL, hematocrit of
29.9%, MCV of 92 fL/red cell, platelet count of 150,000/
/zL, and WBC count of 3800//zL, with a differential count
of 24 segmented neutrophils, 1 band, 64 lymphocytes, 10
monocytes, and 1 eosinophil. He has a reticulocytosis. The
serum haptoglobin level is very low. A mutation in which
of the following gene products could give rise to this
clinical condition?
A Spectrin
B Glucose-6-phosphate dehydrogenase
C Phosphatidylinositol glycan A (PIGA)
D /3-globin chain
E Factor V
urine. He has had multiple bacterial infections over several
years and has a history of venous thromboses, including
portal vein thrombosis in the previous year. A CBC shows
a hemoglobin concentration of 9.8 g/dL, hematocrit of
29.9%, MCV of 92 fL/red cell, platelet count of 150,000/
/zL, and WBC count of 3800//zL, with a differential count
of 24 segmented neutrophils, 1 band, 64 lymphocytes, 10
monocytes, and 1 eosinophil. He has a reticulocytosis. The
serum haptoglobin level is very low. A mutation in which
of the following gene products could give rise to this
clinical condition?
A Spectrin
B Glucose-6-phosphate dehydrogenase
C Phosphatidylinositol glycan A (PIGA)
D /3-globin chain
E Factor V