Hb Dartmouth (HBA2: c.200T>C): An α2-Globin Gene Associated with Hb H Disease in One Homozygous Patient

Abstract

Hb H (β4) disease is caused by deletion or inactivation of three out of four α-globin genes. A high incidence of Hb H disease has been reported all over the world. There is a wide spectrum of phenotypic presentations, from clinically asymptomatic to having significant hepatosplenomegaly and requiring occasional or even regular blood transfusions, even more severe anemia, Hb Bart’s (γ4) hydrops fetalis syndrome that can cause death in the affected fetuses late in gestation. We here present a case who was diagnosed with Hb H disease that represents a new genotype for this hereditary disorder. Hb Dartmouth is a variant caused by a missense mutation at codon 66 of the α2-globin gene (HBA2: c.200T>C), resulting in the substitution of leucine by proline. We here emphasize the importance of this point mutation involving Hb H disease and also the necessity for prenatal diagnosis (PND) for those who carry this point mutation in the heterozygous state.

• α-Thalassemia (α-thal)
• Hb Bart’s hydrops fetalis
• Hb Dartmouth
• Hb H disease
• hepatosplenomegaly

Acknowledgements

We thank all our colleagues in Molecular Department of Kariminejad-Najmabadi Pathology and Genetics Center, Tehran, Iran, for valuable technical assistance and also appreciate the cooperation of all the patients who took part in this study.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.