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To describe rare genetic interactions of α-thalassemia alleles causing Hb H disease and Hb Bart’s hydrops fetalis which could lead to diagnostic errors in a routine practice.Hematological and molecular characterization were carried out in a Thai family with a risk of having fetus with Hb Bart’s hydrops fetalis.Both parents were found to be the thalassemia intermedia patients associated with unusual forms of Hb H disease. DNA analysis of common α-thalassemia mutations in Thailand identified α+-thalassemia (-α3.7 kb del) and unknown α0-thalassemia in the father and α0-thalassemia (--SEA) with unknown α+-thalassemia in the mother. Fetal DNA analysis unlikely identified a homozygosity for α0-thalassemia (--SEA/--SEA). Further analysis identified that the father carried a rare South African α0-thalassemia in combination with α+-thalassemia (--SA/-α), whereas the mother was a patient with Hb H-Queens Park disease (--SEA/ααQP). The fetus was, in fact, a compound heterozygote for (--SA/--SEA).As shown in this study, routine screening for α-thalassemia at prenatal diagnosis in the region should include both common and rare α0-thalassemia alleles found in the population to effectively prevent a fatal condition of Hb Bart’s hydrops fetalis syndrome. [ABSTRACT FROM AUTHOR]

Introduction: Hemoglobinopathies are major public health problems worldwide. Accurate laboratory diagnosis of the carrier is essential, which includes initial screening, Hb analysis, and DNA analysis. For the first time, we have developed a single‐tube quality control (QC) sample for these laboratory tests. Methods: The QC sample was made from a lyophilized mixture of the stabilized hemolysate with carbon monoxide saturation and the white blood cells of known thalassemia mutations. Homogeneity and stability were examined by Hb and DNA analyses on day 0 and every month for 12 months, at room temperature, 4°C, and −20°C. A preliminary proficiency testing (PT) program for hemoglobinopathies using this single QC material was developed. Results: Hemoglobin (Hb) and DNA analyses of a single‐tube QC sample demonstrated satisfactory results of Hb analysis for at least five months and DNA analysis for at least one year of storage at −20°C. The results obtained from a preliminary PT program on five expert laboratories confirmed that a single tube QC sample prepared could be used as a PT item with various Hb and DNA analyses methods. Conclusion: A single lyophilized control sample has been generated for use in hemoglobinopathies' internal and external quality control program. Unlike other available control materials, which are used for individual testing, a single‐tube QC sample generated can be used to control the pre‐analytical and analytical processes of both Hb and DNA analyses and is suitable for use in the PT program of hemoglobinopathies. [ABSTRACT FROM AUTHOR]

Objective Prenatal and postnatal diagnosis of hemoglobin E-β 0-thalassemia can be made using polymerase chain reaction (PCR) analysis mostly on purified DNA. We have establihed a direct amplification method without DNA extraction on whole blood (WB) and amniotic fluid (AF) specimens to diagnose the disease. Methods Three reactions of WB PCR assays and 7 reactions of AF PCR tests were developed for postnatal and prenatal diagnosis, respectively. Assays were validated against routine tests in a blinded trial. Results The results showed 100% concordance with routine DNA PCR assays. Among 309 β-thalassemia carriers, 191 patients (61.8%) carried common β-thalassemia mutations. Among 448 AF specimens, 116 (25.9%) fetuses were found to be affected, 247 (55.1%) fetuses were carriers, and 85 (19%) fetuses were unaffected. Conclusion We found that WB and AF PCR assays are simple, rapid, and reliable. The developed techniques could be applicable in routine settings. [ABSTRACT FROM AUTHOR]

Introduction: A high frequency of β‐thalassemia in Lao People's Democratic Republic necessitates the importance of complete molecular data before a prevention and control program could be established. Limited data are available for Lao PDR. We have now reported an extended information on the molecular basis of β‐hemoglobinopathies in this population. Methods: The study was done on 519 unrelated Laos subjects requested for thalassemia investigation. Hematological data were recorded. Hb profiles were obtained using a capillary electrophoresis system. α‐And β‐globin genotyping was performed using PCR and related techniques. Results: Among the 519 subjects, 287 (55.3%) were found to carry β‐hemoglobinopathies based on Hb and DNA analyses. These included Hb E carriers (n = 135), homozygous Hb E (n = 47), β‐thalassemia carriers (n = 70), Hb E‐β‐thalassemia (n = 25), homozygous β‐thalassemia (n = 4), heterozygous δβ0‐thalassemia (n = 2), and carriers of the β‐Hb variant (n = 3). Mutation analysis identified in addition to the Hb E, 8 different β‐thalassemia mutations including codon 17 (A‐T), codons 41/42 (‐TTCT), NT‐28 (A‐G), codons 71/72 (+A), IVS1‐1 (G‐T), 3.4 kb deletion, an initiation codon (T‐G) and IVS2‐654 (C‐T). Two δβ0‐thalassemia carriers (12.6 kb deletion) and three subjects with Hb Hope (β136GGT‐GAT) were identified. Hematological features associated with these β‐hemoglobinopathies were presented. Conclusion: β‐hemoglobinopathies in the Laos population is heterogeneous. This information is relevant for setting up a molecular diagnostics and can provide a basis for genetic counseling and enable prenatal diagnosis. [ABSTRACT FROM AUTHOR]

We describe hematologic and molecular characteristics of a hitherto undescribed interaction between the Filipino deletional β0-thalassemia with Hb E and α-thalassemia in a Thai family. This study was conducted during the prenatal screening of a pregnant Thai woman and her family members. A prenatal diagnosis was performed at her second pregnancy by amniocentesis. Laboratory investigations identified that the pregnant woman was Hb E heterozygote with α+-thalassemia, whereas her husband was a double heterozygote for the Filipino deletional β0-thalassemia and α+-thalassemia. Their affected son was a patient with a previously undescribed condition of Hb E-β0-thalassemia with α+-thalassemia. Both a combined gap-polymerase chain reaction (PCR) and allele-specific PCR were used successfully in the prenatal diagnosis, which identified an affected fetus with Hb E-β0-thalassemia without α+-thalassemia. Beta globin gene haplotype analysis indicated the same origin of this Filipino β0-thalassemia in Asian populations. [ABSTRACT FROM AUTHOR]

Abstract: α0-thalassemia is the most severe form of α-thalassemia alleles found among Southeast Asian and Chinese populations and can cause a fatal condition known as hemoglobin Bart's hydrops fetalis and hemoglobin H disease. In order to provide the molecular epidemiological characteristic of α0-thalassemia in northeast Thailand, a total of 12,525 blood specimens referred to our center at Khon Kaen University in northeast Thailand during October 2008 to January 2012 were studied. Hematological parameters were recorded and DNA deletions causing α0-thalassemia were examined by PCR related techniques. Among 12,525 samples examined, α0-thalassemia alleles were identified in 1,873 (15.0%) samples, including 1855 (14.8%) cases with Southeast Asian (−−SEA) deletion and 18 cases (0.2%) with THAI deletion (−−THAI). As many as twenty genotypes were encountered. Hb profiles and hematological parameters were comparatively presented. Data on prevalence, molecular features and phenotypic expression of α0-thalassemia should prove useful in a carrier screening and a prevention and control program of this common genetic disorder in the region. [Copyright &y& Elsevier]

Abstract: Study on the phenotypic expression of hemoglobin (Hb) A2 and Hb E in Hb E disorders has been difficult due to the co-separation of Hb A2 and Hb E in most Hb analysis assays. Because these two Hbs are separated on capillary electrophoresis, we studied phenotypic expression of Hbs A2, E and F in various Hb E disorders using this system. This was done on 362 subjects with several Hb E disorders including heterozygous Hb E, homozygous Hb E, β-thalassemia/Hb E, δβ-thalassemia/Hb E, and Hb Lepore/Hb E and those of these disorders with several forms of α-thalassemia. Normal controls showed Hb A2 of 2.7±0.3%. Heterozygous Hb E and homozygous Hb E had elevated Hb A2 i.e. 3.8±0.3% and 4.8±0.5%, respectively. Further elevations were observed for β0-thalassemia/Hb E (6.1±1.9%) and β+-thalassemia/Hb E (7.1±1.2%). Interestingly, no elevation of Hb A2 was found in the δβ-thalassemia/Hb E, and Hb Lepore/Hb E (2.3±0.3%) but higher Hb F levels were noted which could be useful diagnostic markers. The levels of Hb E were variable. Co-inheritance of these Hb E disorders with α-thalassemia were associated with lower outputs of Hb E and Hb F but the levels of Hb A2 were not altered. Different phenotypic expression of Hb A2, Hb E and Hb F could help in differential diagnosis of these Hb E related disorders commonly encountered in the regions where access to molecular techniques is limited. [Copyright &y& Elsevier]

Objective: The degree of ineffective erythropoiesis is known to be associated with clinical severity among individuals with thalassemia. The association of ineffective erythropoiesis biomarker levels with different thalassemia genotypes, however, remains limited. The aim of this study was to explore the level of phosphatidylserine-exposed red blood cells (PS-exposed RBCs) and ineffective erythropoiesis biomarkers (growth-differentiation factor-15 and soluble transferrin receptors) in patients with different genotypes., Methods: A cross-sectional study was conducted on 139 patients of age 18 years and above with different genotypes at Srinagarind Hospital, Khon Kaen University, Thailand. The levels of PS-exposed RBCs were determined using flow cytometry. Measurements of growth-differentiation factor-15 (GDF-15) and soluble transferrin receptors (sTfR) were evaluated by the ELISA method., Results: The PS-exposed RBCs levels were found to be significantly higher in splenectomized beta-thalassemia patients. Patients with beta-thalassemia had the highest GDF-15 levels, followed by patients with non-deletional alpha-thalassemia. Patients with non-deletional alpha-thalassemia showed elevated hemoglobin levels and reduced GDF-15 levels after splenectomy. Patients with beta-thalassemia and non-deletional alpha-thalassemia had the highest levels of PS-exposed RBCs and ineffective erythropoiesis biomarkers, which correlated with the clinical severity of thalassemia., Conclusions: The levels of ineffective erythropoiesis biomarkers were different across thalassemia genotypes. Splenectomy may improve clinical symptoms of patients with non-deletional alpha thalassemia but not of patients with beta-thalassemia. These findings demonstrate differences in the degree of ineffective erythropoiesis in thalassemia, which emphasizes the need for different treatment approaches among patients with different thalassemia genotypes., Competing Interests: None., (AJTR Copyright © 2022.)