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Background The World Health Organization and the American and Canadian Diabetes Associations approved HbA1c > 6.5% as diagnostic for type 2 diabetes mellitus (T2DM). Hb variants and/or their chemically modified species can interfere with HbA1c measurements. We recently described a patient with Hb Wayne trait who was misdiagnosed with T2DM based on falsely elevated HbA1c. Hb Wayne is a clinically silent variant that exists as two isoforms: Hb Wayne I (Asn 139) and Hb Wayne II (Asp 139). Methods Hemoglobinopathy investigation was performed by HPLC (Bio-Rad VARIANT-II), alkaline and acid electrophoresis (Sebia Hydrasis2), capillary zone electrophoresis (Sebia CAPILLARYS2™) and DNA sequencing. HbA1c was measured by five methods. Results Hb Wayne eluted as two small fractions with retention times of 1.0 and 1.46 min on the HPLC (Bio-Rad VARIANT-II). Alkaline gel and capillary electrophoresis showed two small bands migrating faster than HbA. Hb Wayne generated spuriously high results on the Bio-Rad VARIANT-II Turbo 2.0, no results on the Tosoh G8, and did not interfere with either the Sebia CAPILLARYS2™ or immunoassays from Roche (tinaquant) and Siemens (Bayer DCA2000 +). Based on the Hb Wayne HPLC profile of 3 patients, an algorithm was developed to facilitate its detection, which identified 9 additional patients with Hb Wayne trait. Conclusions We characterize Hb Wayne by chromatographic and electrophoretic techniques and show the effect of Hb Wayne on five common HbA1c methodologies. We developed a quality assurance tool to assist in detecting Hb Wayne trait during HbA1c analysis on the Bio-Rad VARIANT-II™ Turbo 2.0. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The increase in hemoglobin (Hb) F level is variably associated to the presence of beta thalassemia trait, and is more typical in presence of δβ thalassemia and of hereditary persistence of fetal hemoglobin. In normal healthy subjects variable levels of HbF are related to the presence of the polymorphism Gγ −158 (C>T). Moreover, HbF can also be variably increased in association with other acquired conditions. The objective of this work is to review the role of the determination of HbF in various conditions. Design and methods: In the present document we comment on the need for accuracy and standardization, and on the interpretation of the HbF value, reviewing most crucial aspects related to this test. Results: We present a practical flow-chart summarizing the significance of the HbF estimation in different thalassemia syndromes and related hemoglobinopathies. Conclusion: The determination of HbF is relevant for the final diagnosis of various physiopathological conditions. In our opinion its importance will increase in the following years, because of the proliferation of novel approaches for the induction of HbF synthesis as a cure for thalassemia syndromes. [Copyright &y& Elsevier]

Abstract: Prenatal diagnosis for the hemoglobinopathies based on molecular analysis of trophoblast or amniocyte DNA has accumulated around 30 years of experience, following the first applications in the 1970s. As the first monogenic diseases to be characterized at the molecular level the disorders of hemoglobin synthesis (thalassemias and hemoglobinopathies) have been used as a prototype for the development of many techniques of mutation detection, and consequently there are numerous PCR-based techniques described in the literature that can be used for prenatal diagnosis of the globin gene mutations. This review describes the most commonly used current methods, as well as the most promising newer methods. In addition, it outlines the newer application of preimplantation genetic diagnosis (PGD) and the state of progress in the developing field of non-invasive prenatal diagnosis. [Copyright &y& Elsevier]

Abstract: Background and objective: The inherited hemoglobinopathies are a large group of disorders that include thalassemias and hemoglobin variants. Accurate determination of the carrier phenotype is essential for detecting couples at risk for producing offspring with hemoglobinopathy. Heterozygous β-thalassemia is usually silent at the clinical level. His phenotype is characterized by microcytosis and hypochromia with increased hemoglobin A2 (HbA2) value. Therefore, HbA2 determination plays a key role in screening programs for hemoglobinopathy. The aim of this review is to address and suggest an approach for reducing or abolishing hemoglobinopathy screening mistakes. Design and methods: Quantitative methods for HbA2 value determination, comment on the accuracy of the test and on the interpretation of data were discussed. The most probable diagnostic conclusion based on the HbA2 level, hemoglobin pattern, hematological parameters and iron markers was suggested in this review. Results: Hemoglobinopathies are the only genetic disease where it is possible to detect carriers using hematological findings rather than DNA analysis. However, hematological diagnosis is sometimes presumptive, and in these cases, DNA analysis becomes necessary. Complete screening is based on the detection of red cell indices, HbA2, HbF and hemoglobin variant values. In particular, HbA2 determination plays a key role in screening programs for β-thalassemia because a small increase in this fraction is one of the most important markers of β-thalassemia heterozygous carriers. Conclusion: Genetic factors both related and unrelated to the β- and α-globin gene clusters, iron metabolism, endocrinological disorders, and some types of anemia, together with intra- and inter-laboratory variations in HbA2 determination, may cause difficulties in evaluating this measurement in screening programs for hemoglobinopathies. Therefore, knowledge of all these issues is important for reducing or eliminating the risk of mistakes in screening programs for hemoglobinopathies. [Copyright &y& Elsevier]