Detection of compound heterozygous of hb constant spring and hb q-Thailand by capillary electrophoresis and high performance liquid chromatography

A comparative evaluation of the analytical performances of premier resolution-high-performance liquid chromatography (PR-HPLC) with capillary zone electrophoresis (CZE) assays for the detection of hemoglobin variants and the quantitation of HbA0, A2, E, and F

OBJECTIVES

Hemoglobinopathies, including thalassemia and hemoglobin (Hb) variants, are common hematological disorders in tropical countries. Accurate and precise separation of hemoglobin types and reliable quantitation are necessary for differential diagnosis of these disorders.

METHODS

We have evaluated the analytical performances of premier resolution-high-performance liquid chromatography (PR-HPLC; Trinity Biotech, Co. Wicklow, Ireland) to assist in the presumptive diagnosis of thalassemia and Hb variants commonly found in Southeast Asian countries. HbA0, HbA2, HbE, and HbF levels were separated and quantified in 120 blood samples from unrelated adult subjects and compared with those analyzed by capillary zone electrophoresis (CZE; CAPILLARYS™ 2, Sebia, Norcross, GA, US). The Hb analysis patterns of Hb variants obtained from the PR-HPLC system were also compared to those obtained from HPLC (VARIANT II, β-thalassemia Short Program, Bio-Rad, Laboratories, Hercules, CA, US) and CZE systems.

RESULTS

The PR-HPLC had excellent precision with a coefficient of variation (CV) for HbA2 quantitation of 3.8 % within-run and 5.2 % between-run. The levels of HbA2/E quantified by the PR-HPLC system correlated well with those of the CZE system (r=0.997). In addition, thalassemia interpretation results obtained from the PR-HPLC and the CZE showed 100 % agreement. Moreover, chromatograms of the PR-HPLC were also comparable to those of VII-HPLC and CAP2-CZE electropherograms.

CONCLUSIONS

The PR-HPLC system would be applicable to diagnose common forms of thalassemia and Hb variants in Southeast Asia.

First Detection of Hb Cenxi [β46(CD5)Gly→Arg (GGG>CGG), HBB: c.139G>C] by Capillary Electrophoresis

We report a novel mutation on the β-globin gene in a female of the Chinese population. This mutation produces a β-globin variant that can be detected by the capillary electrophoresis (CE) method, but coelutes with Hb A₂ by high performance liquid chromatography (HPLC). DNA sequencing showed a mutation of codon 46 and it was named Hb Cenxi [β46(CD5)Gly→Arg (GGG>CGG), HBB: c.139G>C] for the city of birth of the proband. She presented normal hematological parameters.