Analysis of hematological phenotype and genotype of 23 patients from Guangdong with co-inherited hemoglobin Hb Westmead and β-thalassemia

Abstract

To analyze the genotype-phenotype correlation among carriers from Guangdong with co-inherited hemoglobin Hb Westmead (HbWS) and β-thalassemia. Twenty three patients (including 9 males and 14 females, aged 1-53 year old) were diagnosed by hematological analysis and genetic testing. Complete blood cell count and hemoglobin electrophoresis analysis were performed on a XE4000i automatic hemocyte analyzer. Hb, HbF and HbA2 were tested by high performance liquid chromatography (HPLC). Gap-PCR was adopted to detect three common thalassemia deletions. Reverse dot-blotting (RDB) assay was applied for detecting three common non-deletional α2 gene mutations and β-thalassemia. Among the 23 patients, 12 showed anemia, among whom 9 had mild anemia and 3 had moderate anemia. The lowest Hb was 68 g/L, and both mean corpuscular volume and mean corpuscular hemoglobin were lower than average, while HbA2 was higher than 3.5%. Genetic analysis confirmed that 5 cases had αWS-α/α-α, β CD654/β N (21.7%), 4 had α WS-α/α-α, β CD41-42/β N (17.4%), 5 had α WS-α/α-α, β CD17/β N (21.7%), 4 had α WS-α/α-α, β CD28/β N (17.4%), 1 had α WS-α/α-α, β CD71-72/β N (4.3%), 1 had αWS-α/α-α, β CD27-28/β N (4.3%), 1 had α WS-α/α-α, β CD41-42/β CD17 (4.3%), 2 had a concomitant β-thalassemia heterozygosity and -α 3.7 deletion. Patients with co-existing Hb WS and other β-thalassemia trait may show variable clinical features. Such compound heterozygotes are usually misdiagnosed during screening by hemoglobin electrophoresis, accurate diagnose should be attained by molecular diagnosis.