Hb Gunma (βGunma) with Pulmonary Embolism

A 67-year-old woman with pulmonary embolism was suspected to have β-thalassemia based on microcytosis, hemolysis and a negative red cell stability test. The DNA sequencing analysis of β-globin gene, however, revealed the deletion of three nucleotides within codon 127-128, leading to substitution of glutamine and alanine residues at 127 and 128 by proline, namely Hb Gunma. This mutant is characterized by the fact that no abnormal hemoglobin is detected in the circulating blood, and is classified as a thalassemic hemoglobinopathy. The present case showed a relatively hemolytic manifestation. (Internal Medicine 34 : 376-379, 1995)