A 6-year-old girl with Hemoglobin H disease

Abstract

Hemoglobin H (HbH) disease is the severe nonfatal form of α-thalassemia syndrome. It is usually caused by molecular defects of 3 of 4 α-globin genes (--/-α) which cause α-globin expression to be decreased. HbH disease is rare in Japan. Here, we report on a 6-year-old girl with HbH disease who had profound hypochromatic and microcytic anemia. Analysis of the α- globin genes of the patient's family showed that the father, who was Japanese, had an abnormal gene with a 3.7-kb deletion (-α 3.7/αα), and the mother, who was Filipino, had a deletion removing both α-globin genes of the Filipino type (-- FIL/αα). Neither parent had anemia. The patient was found to have HbH disease with a heterozygous genetic abnormality (-- FIL/-α 3.7). Recently, the number of marriages of Japanese to natives of areas where thalassemia is epidemic has increased. Therefore, the incidence of HbH disease can be expected to increase in Japan. Long-term follow-up will be needed to evaluate the long-term complications and to improve the quality of life of patients with HbH disease.