An unstable hemoglobin, Hb Iwata, F8 (α87) His → Arg, was discovered during a screening program for hemoglobin anomalies in the newborns. Studies of the family members of the proband revealed the father and the paternal grandmother to also carry the abnormal hemoglobin. None of the carriers of the abnormal hemoglobin manifested clinical symptoms, probably because Hb Iwata migrated between Hb A and A_2 in starch gen electrophoresis (pH 8.6), and was isolated by DE-52 column chromatography. Analysis of the amino acid composition of tryptic peptides from the α chain of Hb Iwata demonstrated the substitution of the proximal histidine by arginine. Results of the isopropanol, heat denaturation and Heinz body formation tests indicated instability of Hb Iwata. Hb Iwata rapidly auto-oxidized into semihemichrome and subsequently precipitated. The oxidation also accelerated heme loss, and the heme-depleted Hb Iwata tended to dessociate in reference to stereochemical properties other abnormal hemoglobins with substitution of the proximal or distal histidine.
duodenal polyp
tumor of the duodenum
hamartoma of the dumodenum
duodenal adenoma