Hb Westmead (HBA2: c.369C>G): Hematological Characteristics in Heterozygotes with and without α⁰-Thalassemia

Abstract

Hb Westmead (α122(H5)His>Gln) (HBA2: c.369C>G) is a common α-globin variant causing α-thalassemia (α-thal) in Mainland China. In this study, we report the hematological characteristics in Hb Westmead carriers in a Chinese population. There were 546 individuals carrying Hb Westmead based on their molecular diagnosis: 514 Hb Westmead heterozygotes and 32 compound heterozygotes for Hb Westmead and α⁰-thal. Compared to common deletional α⁺-thal, Hb Westmead was associated with higher mean corpuscular hemoglobin (Hb) (MCH) values. Compound heterozygotes for Hb Westmead and α⁰-thal showed significantly higher Hb, mean corpuscular volume (MCV) and MCH values than subjects with deletional Hb H disease. When compared to α⁰-thal carriers, compound heterozygotes for Hb Westmead and α⁰-thal showed similar Hb values, but significantly lower MCV and MCH values. Our results indicate that Hb Westmead is a silent nondeletional α⁺-thal, with a deficiency of α-globin chain milder than deletional α⁺-thal, and compound heterozygotes for Hb Westmead/α⁰-thal have a phenotype similar to simple α⁰-thal.

Keywords:

• α⁰-Thalassemia (α⁰-thal)
• Hb H disease
• Hb Westmead
• mean corpuscular volume (MCV)

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 the Guangzhou Institute of Pediatrics/Guangzhou Women and Children’s Medical Center, Guangzhou, Guangdong Province, People’s Republic of China [IP-2019-004] and the Guangdong Science and Technology Department, Guangzhou, Guangdong, People’s Republic of China [2017A030223003].