Two α1-Globin Gene Point Mutations Causing Severe Hb H Disease

Abstract

Hb H disease is generally a moderate form of α-thalassemia (α-thal) that rarely requires regular blood transfusions. In this study, two Chinese families with members carrying transfusion-dependent Hb H disease were investigated for rare mutations on the α-globin genes (HBA1, HBA2). In one family, Hb Zürich-Albisrieden [α59(E8)Gly→Arg; HBA1: c.178G>C] in combination with the Southeast Asian (– –^SEA) deletion was the defect responsible for the severe phenotype. In another family, a novel hemoglobin (Hb) variant named Hb Sichuan (HBA1: c.393_394insT), causes α-thal and a severe phenotype when associated with the – –^SEA deletion. As these two HBA1 mutations can present as continuous blood transfusion-dependent α-thal, it is important to take this point into account for detecting the carriers, especially in couples in which one partner is already a known α⁰-thal carrier.

Keywords:

• HBA1
• Hb Sichuan
• Hb Zürich-Albisrieden
• transfusion-dependent Hb H disease

Disclosure statement

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

Additional information

Funding

This study was supported by grants from the NSFC (National Natural Science Foundation of China) [81571448] and the Guangdong Provincial Department of Science and Technology Agency [2016A020215218].