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

Hb Westmead (alpha 122(H5)His>Gln) (HBA2: c.369C>G) is a common alpha-globin variant causing alpha-thalassemia (alpha-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 alpha(0)-thal. Compared to common deletional alpha(+)-thal, Hb Westmead was associated with higher mean corpuscular hemoglobin (Hb) (MCH) values. Compound heterozygotes for Hb Westmead and alpha(0)-thal showed significantly higher Hb, mean corpuscular volume (MCV) and MCH values than subjects with deletional Hb H disease. When compared to alpha(0)-thal carriers, compound heterozygotes for Hb Westmead and alpha(0)-thal showed similar Hb values, but significantly lower MCV and MCH values. Our results indicate that Hb Westmead is a silent nondeletional alpha(+)-thal, with a deficiency of alpha-globin chain milder than deletional alpha(+)-thal, and compound heterozygotes for Hb Westmead/alpha(0)-thal have a phenotype similar to simple alpha(0)-thal.