Hemoglobin H disease induced by the common SEA deletion and the rare hemoglobin Quong Sze in a Thai female: longitudinal clinical course, molecular characterization, and development of a PCR/RFLP-based detection method

摘要

We report on a Thai female patient who presented with hypochromic microcytic anemia, hepatosplenomegaly, and failure to thrive since 3 years of age. Hematological and hemoglobin (Hb) analysis were consistent with a clinical diagnosis of Hb H disease. However, no abnormal Hb fraction had ever been detected. During the 20 years of follow-up, this patient experienced several episodes of hemolytic crisis, which worsened her anemia, necessitating blood transfusion. Recently, we identified Hb Quong Sze (Hb QS), a highly unstable globin gene mutation affecting codon 125 (CTG→CCG) of α2 globin gene in trans with the commonest α0 thalassemia (–SEA) in the patient. This report highlights the clinical significance of Hb QS in Southeast Asians, as previously almost all of the patients described with this variant were of Chinese origin.