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We describe hematologic and molecular characteristics of a hitherto undescribed interaction between the Filipino deletional [beta](0)-thalassemia with Hb E and [alpha]-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 [alpha](+)-thalassemia, whereas her husband was a double heterozygote for the Filipino deletional [beta](0)-thalassemia and [alpha](+)-thalassemia. Their affected son was a patient with a previously undescribed condition of Hb E-[beta](0)-thalassemia with [alpha](+)-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-[beta](0)-thalassemia without [alpha](+)-thalassemia. Beta globin gene haplotype analysis indicated the same origin of this Filipino [beta](0)-thalassemia in Asian populations. [ABSTRACT FROM AUTHOR]

To establish simple noninvasive prenatal diagnosis of common beta-thalassemia in Southeast Asia, we have evaluated the possibility of identifying the 3 most common beta-thalassemia genes [beta(E), beta(17A-T), and beta(41/42(-CTCC))] by analysis of fetal DNA in maternal plasma using combined conventional polymerase chain reaction (PCR) and real-time quantitative PCR. Maternal plasma was obtained from peripheral blood of Thai pregnant women collected during the first and second trimesters of gestation. DNA was prepared from 200 muL plasma using a QIAmp Blood Mini Kit. Identifications of the beta(E), beta(41/42(-CTTT)), and beta(17A-T) in plasma DNA were carried out using semi-nested (for beta(E)) and nested (for beta(41/42) and beta(17)) real-time allele-specific PCR methodologies, and the results were compared with those obtained on fetal tissue analysis with routine invasive procedure. Twenty-six fetal beta(E) genes were correctly identified by maternal plasma DNA analysis of 39 pregnant women investigated. The fetal beta(41/42) and beta(17) mutations were detectable in 6 of 12 and 4 of 9 maternal plasma specimens, respectively, which were in concordance with the results obtained by routine invasive procedure. The noninvasive prenatal diagnostic methods developed should potentially prove useful for detection of paternally inherited mutation and for providing the exclusion of pregnancies at risk for this common genetic disorder in the region. [ABSTRACT FROM AUTHOR]

BACKGROUND: It is customary in Southeast Asia to treat pregnant anemic women with iron supplements, but anemia in this region may be complicated by thalassemia and hemoglobinopathies, which lead to an ineffective response. OBJECTIVE: The aim was to determine whether routine iron supplementation during pregnancy in this area, which has a high prevalence of thalassemia and hemoglobinopathies, is an effective control strategy for iron deficiency anemia. DESIGN: A prospective study was conducted. Seventy-six pregnant women, including 43 who were heterozygous for the hemoglobin E (Hb E) gene, 20 who were heterozygous for Hb E and had alpha-thalassemia, and 13 who were homozygous Hb E, as well as 77 pregnant women who had no thalassemia gene, participated in this investigation. All pregnant women received a daily dose of 120 mg elemental Fe for an average of 133.5 d. Hematologic variables and serum ferritin concentrations were measured before supplementation and after supplementation at the gestational age of 28-32 wk. Differences in hematologic variables and serum ferritin were assessed. RESULTS: Significant differences in hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin responses were found between the nonthalassemia group and the 3 groups with the Hb E gene after adjustment for the following baseline values: age, body mass index, duration of iron supplementation, and ferritin concentration. Significant differences in the improvements in mean corpuscular volume and mean corpuscular hemoglobin values between the 3 groups indicate a poorer response at the cellular level in the pregnant women with the Hb E gene. Further analysis showed a significant difference in the hemoglobin response only for women who were homozygous for Hb E. CONCLUSION: Iron supplementation during pregnancy is not beneficial for pregnant women who are homozygous for Hb E, but a routine intervention should not cause iron overload, as judged from this short observation period. Copyright © 2007 American Society for Nutrition [ABSTRACT FROM AUTHOR]

Objective: To evaluate a simple screening strategy for thalassaemia and haemoglobin (Hb) E in a prevention and control programme for thalassaemia in rural communities with limited resources. Methods: Blood samples from 301 Thai-Khmer participants were screened for thalassaemia and Hb E using a combined modified one-tube osmotic fragility (OF) test and a modified dichlorophenolindophenol (DCIP) precipitation test. Results were evaluated with standard haemotological analyses including erythrocyte indices, Hb typing and quantification and polymerase chain reaction (PCR) analysis of [alpha]-globin and -globin genes. Findings: Participants were divided into four groups according to the results of the combined tests. Altogether, 104 of 301 participants (34.6%) had negative results on both tests; 48 (15.9%) were positive on the OF test but not the DCIP test; 40 (13.3%) were negative thalassaemia ([alpha]o-thalassaemia, thalassaemia) or Hb E was found among the group that had negative results for both tests. All participants with Hb E had positive DCIP tests. Carriers of [alpha]+-thalassaemia or Hb Constant Spring could generate either positive or negative OF test results but they all had negative DCIP tests. Using both tests as a preliminary screening for the three important groups of carriers gave a sensitivity of 100% and a specificity of 69.8%. The positive predictive value of the combined test was 77.2%. The negative predictive value was 100%. Further evaluation of the screening system by local staff at three community hospitals found a sensitivity of 98.1-100% and a specificity of 65.4-88.4% with positive predictive values of 75.0-86.9% and negative predictive values of 98.1-100%. Conclusion: A combined test using OF and DCIP could be used as an effective preliminary screening alternative to an electronic blood cell count for identifying carriers with [alpha]o-thalassaemia, -thalassaemia and Hb E. The strategy should prove useful for population screening in prevention and control programmes in rural communities in south-east Asia where laboratory facilities and economic resources are limited. [ABSTRACT FROM AUTHOR]

Hemoglobin (Hb) Korle-Bu (β73; Asp-Asn) is the most frequent of the rare β-chain variants in the population of West Africa whereas Hb E (β26; Glu-Lys) is common among the Southeast Asian population. We report a hitherto undescribed condition in which these two β-chain variants co-segregate. The proband was a 19-year-old Thai pregnant woman in her second trimester of pregnancy who visited our thalassemia screening unit. Cellulose acetate electrophoresis and high-performance liquid chromatography (HPLC) analysis of Hb detected one abnormal Hb in addition to the Hb E. Analysis of DNA sequences revealed a GAT-AAT mutation at codon 73 in trans to a GAG-AAG mutation at codon 26 of the β-globin gene. Polymerase chain reaction (PCR) analysis of the α-globin gene cluster of the patient detected a 3.7-kb deletional α-thalassemia 2. Family study identified that her mother had the same genotype and her father was a simple Hb E carrier. The hematological data of these unusual cases of hemoglobinopathy are presented and compared with a simple heterozygote for Hb Korle-Bu found in another unrelated Thai family. β-Globin gene haplotype linked to the Thai βKorle-Bu and a simple DNA assay based on allele-specific PCR for rapid diagnosis of Hb Korle-Bu are also described. [ABSTRACT FROM AUTHOR]

We report the haematological and molecular characterization of a previously undescribed condition of compound heterozygosity for haemoglobin (Hb) Hekinan [α27(B8) Glu-Asp] and a deletionalα-thalassaemia 2 detected in a Thai individual. Hb analysis demonstrated that although this Hb variant co-migrates with Hb A on cellulose acetate electrophoresis and cation-exchange high-performance liquid chromatography (HPLC), the HPLC procedure using a weak cation-exchange material with polyaspartic acid could clearly differentiate the two Hb. The variant could then be confirmed using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) analysis of the amplifiedα1-globin gene. [ABSTRACT FROM AUTHOR]

Objectives: This study reported a large cohort of fetal blood analysis of various hemoglobinopathies., Methods: A total of 371 fetal blood specimens were recruited. Complete blood count and hemoglobin (Hb) analysis using capillary electrophoresis were performed. Genotypes were defined by DNA analysis., Results: Among 371 fetuses, 36 were non-thalassemic and 29 thalassemia genotypes were identified in the remaining 335 fetuses. Fetuses with β-thalassemia and Hb E traits, homozygous Hb E, and Hb E-β 0 -thalassemia had similar hematological parameters as those of non-thalassemic. However, the levels of Hb A in β-thalassemia and Hb E traits were approximately half of that observed in the non-thalassemic fetuses. As for Hb E, fetuses with a single copy of the β E -globin gene in the Hb E trait and Hb E-β 0 -thalassemia had lower Hb E levels as compared to that of the homozygous Hb E. For α-thalassemia, fetuses with one or two α-globin gene defects had small changes in hematological parameters, but variable Hb Bart's levels were observed. Fetuses with Hb H and Hb H-CS diseases had moderate anemia, whereas those with homozygous Hb CS and Hb Bart's hydrops fetalis had severe anemia. Identification of the fetuses with Hb Bart's hydrops fetalis with various genetic interactions allows the exact re-location of electrophoretic mobilities of various embryonic Hbs., Conclusions: This study confirmed the genetic heterogeneity of hemoglobinopathies among the fetuses and fetal blood analysis are useful for presumptive diagnosis of hemoglobinopathies. The results should facilitate a prevention and control program of hemoglobinopathies in the region., (© 2025 Walter de Gruyter GmbH, Berlin/Boston.)

Objectives: 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., Methods: Hematological and molecular characterization were carried out in a Thai family with a risk of having fetus with Hb Bart's hydrops fetalis., Results: 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 (-α 3.7 kb del ) and unknown α 0 -thalassemia in the father and α 0 -thalassemia (-- SEA ) with unknown α + -thalassemia in the mother. Fetal DNA analysis unlikely identified a homozygosity for α 0 -thalassemia (-- SEA /-- SEA ). Further analysis identified that the father carried a rare South African α 0 -thalassemia in combination with α + -thalassemia (-- SA /-α), whereas the mother was a patient with Hb H-Queens Park disease (-- SEA /αα QP ). The fetus was, in fact, a compound heterozygote for (-- SA /-- SEA )., Conclusions: As shown in this study, routine screening for α-thalassemia at prenatal diagnosis in the region should include both common and rare α 0 -thalassemia alleles found in the population to effectively prevent a fatal condition of Hb Bart's hydrops fetalis syndrome., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

Background: Anemia is a globally well-known major public health problem. In Southeast Asia where there is ethnic diversity, both iron deficiency (ID) and inherited hemoglobin disorders (IHDs) are prevalent and are considered to be the major factors contributing to anemia. However, little is known about the anemia burden among the ethnic minorities. In this study, we determine the burden of anemia, in relation to ID and IHDs, among the Karen ethnic minorities living in the rural area of lower northern Thailand., Methods: A cross-sectional community-based study was conducted at Ban Rai district, Uthai Thani province. Study participants included 337 Karen people aged over 18 years. Socio-economic and health-related information were obtained through interviews and recorded by local health staff. Anemia, IHDs and ID were diagnosed according to standard laboratory methods. Multivariate logistic regression analysis was applied to identify risk factors of moderate-to-severe anemia., Results: The prevalence of overall anemia was 27.9% (95% CI = 23.2-33.0). Mild and moderate anemia were detected in 18.7% (95% CI = 14.7-23.3) and 8.9% (95% CI = 6.1-12.5) respectively. Severe anemia was found in one case (0.3%). Various forms of IHDs were identified in 166 participants, constituting 49.3% (95% CI = 43.8-54.7). The most common form of IHDs was α+-thalassemia (32.9%), followed by β-thalassemia (12.2%), α0-thalassemia (4.2%), hemoglobin E (3.9%), and hemoglobin Constant Spring (0.9%). Among 308 participants who were investigated for ID, the prevalence was discovered to be 6.8% (95% CI = 4.3-10.2). Analysis of risk factors of moderate-to-severe anemia revealed that individuals with ID, β-thalassemia and age > 65 years were at high risk with adjusted odds ratio of 17 (95% CI = 3.8-75.2), 6.2 (95% CI = 1.4-27.8) and 8.1 (95% CI = 1.6-40.4) respectively., Conclusions: Anemia among the Karen is of public health significance; and IHDs are the major contributing factors. Because of the high risk of developing moderate-to-severe anemia, special attention should be paid to individuals affected with ID, β-thalassemia and the elderly. Public awareness of the health burden of severe thalassemia syndromes should also be campaigned., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Pyae et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: The wide variation in hemoglobin (Hb) F levels has been observed in patients with Hb EE disease. This study aimed to describe hematologic features and determine the effect of genetic variants on Hb F expression in young children with Hb EE disease., Methods: Hematologic features and Hb profiles of Laotian children aged 6-23 months, who originally enrolled in the Lao-Zinc study, were retrospectively reviewed. Only children with Hb EE disease, as indicated by DNA analysis, were included in this current analysis. Genetic variants, including the G γ-XmnI polymorphism (C>T) of the HBG2 gene, the HBS1L-MYB intergenic region on chromosome 6, and the BCL11A on chromosome 2 as well as the mutations occurring on the Krüppel-like factor 1 (KLF1) gene, were examined., Results: In total, 205 children were diagnosed as having Hb EE disease with Hb F ranged from 1.2 to 43.7%. Most of the children had mild to moderate anemia with a remarkable microcytosis. Analysis of the genetic variants revealed an extremely high frequency of the G γ-XmnI (93.7%). Applying multiple regression analysis adjusted for age, sex, and α-thal gene, a positive relation was observed for the rs4671393 (coefficient = 3.87, p = .005) and the rs2297339 (coefficient = 2.48, p = .046), but not the G γ-XmnI. A statistically non-significant relation was noted for the rs9399137 and the -154 (C>T) KLF1 mutation., Conclusion: Our findings provide insight into complex situation of Hb F variability in young children with Hb EE disease; and this can guide to appropriate care and counseling to affected families., (© 2023 John Wiley & Sons Ltd.)

Objective: To determine the frequency and etiology of unnecessary prenatal diagnosis for hemoglobinopathies during 12 years of services at a single university center in Thailand., Methods: We conducted a retrospective cohort analysis of prenatal diagnosis during 2009-2021. A total of 4,932 couples at risk and 4,946 fetal specimens, including fetal blood (5.6%), amniotic fluid (92.3%), and chorionic villus samples (2.2%) were analyzed. Identification of mutations causing hemoglobinopathies was carried out by PCR-based methods. Maternal contamination was monitored by analysis of the D1S80 VNTR locus., Results: Among 4,946 fetal specimens, 12 were excluded because of poor PCR amplification, maternal contamination, non-paternity, and inconsistency of the results of the fetuses and parents. Breakdown of 4,934 fetuses revealed 3,880 (78.6%) at risk for the three severe thalassemia diseases, including β-thalassemia major, Hb E-β-thalassemia, and homozygous α0-thalassemia, 58 (1.2%) at risk for other α-thalassemia diseases, 168 (3.4%) at risk for β+-thalassemia, 109 (2.2%) at risk for high Hb F determinants, 16 (0.3%) at risk for abnormal Hbs, and 294 (6.0%) with no risk of having severe hemoglobinopathies. The parents of 409 (8.3%) fetuses had inadequate data for fetal risk assessment. Overall, we encountered unnecessary prenatal diagnostic requests for 645 (13.1%) fetuses., Conclusions: The frequency of unnecessary prenatal diagnosis was high. This could lead to unnecessary risk of complications associated with fetal specimen collection, psychological impacts to the pregnant women and their families, as well as laboratory expenses and workload., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Singha et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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., (© 2021 John Wiley & Sons Ltd.)

Objectives: A co-inheritance of α 0 -thalassemia can ameliorate the clinical severity of the hemoglobin (Hb) E-β-thalassemia disease. This information should be provided at prenatal diagnosis. Identification of α 0 -thalassemia in an affected fetus is therefore valuable. We have explored this genetic interaction in a large cohort of affected fetuses with hemoglobin (Hb) E-β-thalassemia in northeast Thailand., Methods: A study was done retrospectively on 1,592 couples at risk of having fetuses with Hb E-β 0 -thalassemia, encountered from January 2011 to December 2019. A total of 415 left-over DNA specimens of the affected fetuses with Hb E-β 0 -thalassemia disease were further investigated. Examination of α 0 -thalassemia was done using gap-PCR or a multiplex PCR assay for simultaneous detection of Hb E and α 0 -thalassemia mutations., Results: Of the 415 affected fetuses, the two most common β 0 -thalassemia genes found were the codons 41/42 (-TTCT) (199/415; 48.0%) and codon 17 (A-T) (115/415; 27.7%). α 0 -thalassemia was found unexpectedly in 21 (5.1%) fetuses. Hematologic phenotypes of the parents indicated that it was impossible to differentiate a pure β 0 -thalassemia carrier from a double β 0 -thalassemia/α 0 -thalassemia heterozygote unless DNA analysis is performed. In contrast, a reduced level of Hb E in the Hb E carrier (<25%) is a valuable marker for predicting double heterozygosity for Hb E/α 0 -thalassemia. This could be further confirmed using a multiplex PCR assay., Conclusions: There is a high prevalence of co-inheritance of α 0 -thalassemia in fetuses with Hb E-β 0 -thalassemia disease. In a high-risk population such as Thailand, we recommend screening for α 0 -thalassemia in all affected fetuses with Hb E-β 0 -thalassemia disease and providing complete genetic information to the parents to make appropriate decisions at prenatal diagnosis and genetic counseling., Competing Interests: None., (AJTR Copyright © 2022.)

Background: To evaluate whether the quantification of fetal hemoglobin (Hb) Bart's is useful for differentiation of α-thalassemia syndromes in the fetus and to characterize the fetal anemia associated with fetal α-hemoglobinopathy., Methods: A total of 332 fetal blood specimens collected by cordocentesis were analyzed using capillary electrophoresis and the amount of Hb Bart's was recorded. The result was evaluated against thalassemia genotypes determined based on Hb and DNA analyses. Prenatal Hb and DNA characterization of the fetal anemia observed in two families was done., Results: Among 332 fetuses investigated, Hb and DNA analyses identified 152 fetuses with normal genotypes. The remaining 180 fetuses carried α-thalassemia with several genotypes. Variable amounts of Hb Bart's were identified in all fetuses with α-thalassemia, which could be used for simple differentiation of fetal α-thalassemia genotypes. These included α + - and α 0 -thalassemia traits, homozygous α + -thalassemia and Hb Constant Spring (CS), Hb H disease, Hb H-CS and Hb H-Quong Sze diseases, homozygous α 0 -thalassemia causing the Hb Bart's hydrops fetalis and a remain uncharacterized α-thalassemia defect. The previously undescribed interactions of Hb Queens Park and Hb Amsterdam A1 with Hb E were detected in two fetuses with Hb Bart's of 0.5%. The Hb Queens Park-AEBart's disease was also noted in one pregnant woman. Prenatal analysis of the fetuses with severe fetal anemia and cardiomegaly with Hb Bart's of 9.0% and 13.6% revealed unexpectedly the homozygous Hb CS and a compound heterozygosity of Hb CS/Hb Pakse' with Hb E heterozygote, respectively., Conclusions: The usefulness of detecting and differentiation of fetal α-thalassemia syndromes by quantifying of Hb Bart's was demonstrated. Apart from the fatal condition of Hb Bart's hydrops fetalis associated with homozygous α 0 -thalassemia, homozygous Hb CS and a compound Hb CS/Hb Pakse' could result in severe fetal anemia and fetal complications, prenatal diagnosis is highly recommended. The simple Hb Bart's quantification of fetal blood should prove helpful in this matter., (© 2022. The Author(s).)

Objective: Increased hemoglobin (Hb) A 2 level is an important diagnostic marker for β-thalassemia carrier screening. The level of Hb A 2 is also useful for differentiating several thalassemia syndromes. We have examined data bases for reduced Hb A 2 expression in a large cohort of Thai subjects., Methods: A study was done on 1,498 subjects with non-thalassemia and various types of thalassemia and Hb variants to determine the effect of thalassemia genotypes and on 103 women of reproductive age to determine the effect of iron deficiency. Hb analysis was done using capillary electrophoresis, and thalassemia genotypes were defined by DNA analysis. Serum ferritin was measured using chemiluminescent microparticle immunoassay., Results: Subjects were divided into 35 groups based on iron status, Hb, and DNA analysis. Decreased Hb A 2 level was observed in those with Hb Q-Thailand, δ-hemoglobinopathies, δβ 0 -thalassemia, Hb Lepore, iron deficiency, α-thalassemia, and especially Hb Constant Spring (Hb CS). While β-thalassemia carriers with Hb H disease still had elevated Hb A 2 levels, most of the β-thalassemia carriers with Hb H-CS disease had Hb A 2 less than 3.5% as a diagnostic cut-off. The lowest Hb A 2 level was observed in those with Hb H-CS disease., Conclusion: Iron deficiency, Hb CS trait, homozygous Hb CS, and Hb H disease may reduce Hb A 2 level, leading possibly to misdiagnosis of β-thalassemia, especially in carriers with borderline Hb A 2 . Hb CS showed the strongest effect on Hb A 2 expression. Understanding the basis for reduced Hb A 2 expression may help reduce the diagnostic pitfalls of β-thalassemia in the region., Competing Interests: None., (AJTR Copyright © 2021.)

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., (© American Society for Clinical Pathology, 2021. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common X-linked enzymopathy, highly prevalent in the areas where malaria is or has been endemic. Prevalence of G6PD deficiency and characterization of G6PD variants in females from previously malaria-endemic areas of northeastern Thailand remain unstudied., Methods: Prevalence of G6PD deficiency was determined by a fluorescent spot test (FST), quantitative G6PD activity assay, and multiplex allele-specific (AS)- and restriction fragment length polymorphic (RFLP)-PCR developed for detection of common G6PD variants in the Thai population., Results: Prevalence of G6PD deficiency in female samples (n = 355) was 18% by FST, 29.6% by quantitation of G6PD activity, and 28.1% by PCR-based genotyping. The most common variant was G6PD Viangchan (54%), followed by G6PD Canton (11%) and G6PD Union (11%); in addition, a novel heterozygous variant, G6PD Khon Kaen (c.305T>C, p.F102S), was identified. The majority of heterozygotes expressed G6PD activity within the intermediate deficiency range (30-70% median of normal enzyme activity)., Conclusion: High prevalence of G6PD deficiency was present in females from northeastern Thailand, the majority being due to heterozygosity of G6PD variants. The findings will have a bearing on the inclusion of primaquine in antimalarial-based policies for malaria elimination in populations with a high prevalence of G6PD deficiency., Competing Interests: Competing interests: The authors declare no conflict of Interest.

Objective: To establish a new indicator derived from reticulocyte hemoglobin (Ret-He) content and red blood cell (RBC) indices for screening for iron deficiency anemia (IDA) in an area in whch thalassemia is prevalent., Methods: Blood specimens from 304 women aged between 18 and 30 years residing in northeast Thailand were collected and measured for RBC and reticulocyte parameters. Iron deficiency was diagnosed when a participant had a serum ferritin level of less than 15 ng per mL. Thalassemia genotypes were defined by hemoglobin (Hb) and DNA analyses., Results: Of the total participants, 25% had iron deficiency (ID) and 50% carried the thalassemia gene. Various mathematical formulas were established and analyzed using the receiver operating characteristic (ROC) curve. The formula derived from Ret-He: (Ret-He/RDW-SD) × 10, was the best predictor for identifying ID among participants (area under the curve [AUC] = 0.812). Further testing of this indicator among individuals with positive thalassemia-screening results revealed stronger performance with an AUC of 0.874., Conclusions: The findings indicate that the formula derived from Ret-He might be applicable for screening ID in areas in which thalassemia is prevalent., (© American Society for Clinical Pathology 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Elevated hemoglobin (Hb) A 2 is an important diagnostic marker for β-thalassemia carriers. However, diagnosis of cases with borderline Hb A 2 may be problematic. We described the molecular characteristics found in a large cohort of Thai subjects with borderline Hb A 2 ., Material and Methods: Examination was done on 21,657 Thai subjects investigated for thalassemia at Khon Kaen University, Thailand. A total of 202 subjects with borderline Hb A 2 (3.5-4.0%) were selectively recruited and hematological parameters were recorded. DNA variants in α-, β-, δ-globin, and Krüppel-like factor 1 ( KLF1 ) genes were examined using PCR., Results: Among 202 subjects, DNA analysis identified carriers of α + -thalassemia ( n = 48; 23.8%), β-thalassemia ( n = 22; 10.9%) and KLF1 mutations ( n = 48; 23.8%). No molecular defect was observed in the remaining 84 (41.5%) subjects. Interaction of KLF1 and α-thalassemia was observed in 10 cases. Of the 22 β-thalassemia carriers, five β + -thalassemia mutations were identified with lower MCV and higher Hb A 2 . Seven KLF1 mutations were detected in 10 genotypes in subjects with higher MCV and Hb F. No β 0 -thalassemia, α-globin gene triplication or δ-globin gene mutation was detected., Conclusions: A large proportion of subjects with borderline Hb A 2 are not β-thalassemia carriers and for those with β-thalassemia, only mild β + -thalassemia mutations were detected. Evaluation of the patients using Hb A 2 , Hb F and MCV values will help in selecting cases for further molecular analysis. The results should explain the unusual phenotype of the cases and facilitate a thalassemia screening program in the region., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2020 Termedia & Banach.)

Introduction: Determination of hemoglobins (Hbs) F, A 2, and E is crucial for diagnosis of thalassemia. This study determined the levels of Hbs F, A 2, and E in children aged 6-23 months and investigated the effect of age, sex, and types of thalassemia on the expression of these Hbs., Methods: A total of 698 blood samples of Laotian children including 272 non-Hb E, 271 Hb E heterozygotes, and 155 Hb E homozygotes were collected. Hb profiles were determined using the capillary zone electrophoresis. Coinheritance of α-thalassemia and the homozygosity for Hb E mutation were checked by PCR-based assay., Results: Children heterozygous and homozygous for Hb E had significantly higher Hb F and A 2 levels than non-Hb E children (median Hb F = 1.1% for non-Hb E group, 2.7% for Hb E heterozygotes, and 9.4% for Hb E homozygotes; median Hb A 2  = 2.6% for non-Hb E group, 3.8% for Hb E heterozygotes, and 5.2% for Hb E homozygotes). The median Hb E levels were 21.9% for Hb E heterozygotes and 85.3% for Hb E homozygotes. Comparing within group, there was a statistically significant difference between children with and without an α-gene defect for Hb A 2 and E, but not Hb F. Based on a multiple regression analysis, age and sex were significantly associated with the expression of Hb F and A 2 but not Hb E., Conclusions: Our findings can guide the development of a diagnostic approach to thalassemia in children aged 6-23 months., (© 2020 The Authors. International Journal of Laboratory Hematology published by John Wiley & Sons Ltd.)

Background: Anaemia and iron deficiency (ID) affect women of reproductive age globally and considered to be a major public health problem in developing countries. This study determines the prevalence of anaemia and ID among women of reproductive age in urban northeast Thailand and examined the relative contribution of various risk factors to anaemia and ID in this population., Methods: Three hundred ninety-nine non-pregnant women, aged 18-45 years, from three universities in northeast Thailand participated in this cross-sectional study. Selected socio-demographic, history of blood loss, usual consumption of red meat and tea/coffee, and anthropometric data were collected. Complete blood count including haemoglobin (Hb) concentration, serum ferritin (SF), C-reactive protein (CRP), and thalassemia were determined. Multiple logistic regressions were applied to identify the risk factors of anaemia and ID., Results: Overall, 370 participants were included for data analyses after excluding women with severe/intermedia thalassemia diseases and/or those with positive serum CRP. The prevalence of anaemia, ID, and iron deficiency anaemia (IDA) were 28.4, 28.4, and 13.2%, respectively. Women with thalassemia had a higher prevalence of anaemia but a lower prevalence of ID than the women without thalassemia. By multiple regression analysis, ID [adjusted OR (AOR) = 4.9, 95% CI = 2.8-8.3], two α-gene defects (AOR = 8.0, 95% CI = 3.0-21.3) and homozygous Hb E (AOR = 8.5, 95% CI = 3.0-24.3) were identified as the potential risk factors of anaemia. Further, the odds of ID were significantly higher among women who donated blood within the past 3 months (AOR = 6.7, 95% CI = 2.8-16.3), and had moderate to a high amount of blood loss during menstruation (AOR = 2.2, 95% CI = 1.3-3.9)., Conclusion: This study found a relatively high but differential prevalence of anaemia and ID among women of reproductive age with or without thalassemia. Only homozygous Hb E and two α-gene defects of thalassemia types and ID were the main factors contributing to anaemia. Recent blood donation, and moderate to a high amount of blood loss during menstruation were potential risk factors of ID in this population.

Some studies found that providing micronutrient powder (MNP) causes adverse health outcomes, but modifying factors are unknown. We aimed to investigate whether Fe status and inherited Hb disorders (IHbD) modify the impact of MNP on growth and diarrhoea among young Lao children. In a double-blind controlled trial, 1704 children of age 6-23 months were randomised to daily MNP (with 6 mg Fe plus fourteen micronutrients) or placebo for about 36 weeks. IHbD, and baseline and final Hb, Fe status and anthropometrics were assessed. Caregivers provided weekly morbidity reports. At enrolment, 55·6 % were anaemic; only 39·3 % had no sign of clinically significant IHbD. MNP had no overall impact on growth and longitudinal diarrhoea prevalence. Baseline Hb modified the effect of MNP on length-for-age (LAZ) (P for interaction = 0·082). Among children who were initially non-anaemic, the final mean LAZ in the MNP group was slightly lower (-1·93 (95 % CI -1·88, -1·97)) v. placebo (-1·88 (95 % CI -1·83, -1·92)), and the opposite occurred among initially anaemic children (final mean LAZ -1·90 (95 % CI -1·86, -1·94) in MNP v. -1·92 (95 % CI -1·88, -1·96) in placebo). IHbD modified the effect on diarrhoea prevalence (P = 0·095). Among children with IHbD, the MNP group had higher diarrhoea prevalence (1·37 (95 % CI 1·17, 1·59) v. 1·21 (95 % CI 1·04, 1·41)), while it was lower among children without IHbD who received MNP (1·15 (95 % CI 0·95, 1·39) v. 1·37 (95 % CI 1·13, 1·64)). In conclusion, there was a small adverse effect of MNP on growth among non-anaemic children and on diarrhoea prevalence among children with IHbD.

Objective: The 3.7 kb deletion (-α 3.7 ) is the most common form of α + -thalassemia found in multiple populations which can be classified into three subtypes. In order not to mis-identify it, the molecular information within each population is required. We have addressed this in northeast Thai and Laos populations., Methods: Screening for α + -thalassemia was initially done on 1192 adult Thai subjects. In addition, 77 chromosomes of Thai newborns and 26 chromosomes of Laos with -α 3.7 α + -thalassemia were also examined. All subjects were screened for -α 3.7 α + -thalassemia and subtyped by PCR-RFLP assay. Exact deletion breakpoint of each -α 3.7 subtype was determined by DNA sequencing. α-Globin gene haplotypes were determined., Results: The proportions of -α 3.7 subtypes found in 216 Thai -α 3.7 chromosomes were 94.9% for -α 3.7I , 4.2% for α 3.7II and 0.9% for -α 3.7III . All 26 Laos -α 3.7 chromosomes were of -α 3.7I variety. At least six α-globin gene haplotypes were associated with the -α 3.7I α + -thalassemia., Conclusion: All -α 3.7 subtypes were observed among Southeast Asian population. Haplotype analysis indicated a multiple origin of this common disorder in the region. A multiplex PCR assay has been developed for simultaneous detection of all subtypes of -α 3.7 α + -thalassemia as well as other α + -thalassemia found in the region including -α 4.2 α + -thalassemia, Hb Constant Spring and Hb Paksé., (Copyright © 2019 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Background: The finding of many Thai Hb E-β 0 -thalassemia patients with non-transfusion dependent thalassemia (NTDT) phenotype without co-inheritance of α-thalassemia has prompted us to investigate the existence of other genetic modifying factors., Methods: Study was done on 122 adult Thai patients with NTDT Hb E-β-thalassemia patients without co-inheritance of α-thalassemia. Multiple single-nucleotide polymorphisms (SNPs) associated with γ-globin gene expression including the G γ- Xmn I of HBG2 gene, rs2297339, rs4895441, and rs9399137 of the HBS1L-MYB gene, rs4671393 in the BCL11A gene, and G176AfsX179, T334R, R238H and -154 (C-T) in the KLF1 gene were investigated using PCR and related techniques., Results: Heterozygous and homozygous for G γ- Xmn I of HBG2 gene were detected at 70.5% and 7.4%, respectively. Further DNA analysis identified the rs2297339 (C-T), rs4895441 (A-G), and rs9399137 (T-C) of HBS1L-MYB gene in 86.9%, 25.4%, and 23.0%, respectively. The rs4671393 (G-A) of the BCL11A gene was found at 31.2%. For the KLF1 gene, only T334R was detected at 9.0%., Conclusions: It was found that these SNPs, when analyzed in combination, could explain the mild phenotypic expression of all cases. These results underline the importance of these informative SNPs on phenotypic expression of Hb E-β-thalassemia patients., Competing Interests: Competing interests: The authors have declared that no competing interests exist.

This study assessed thalassemia and hemoglobinopathies in a group of the Tay ethnic minority. Participants included 289 women of reproductive-age who enrolled in a pilot screening program for thalassemia conducted at six communities of Thai Nguyen Province, northern Vietnam. Standard procedures including complete blood count (CBC), hemoglobin (Hb) and DNA analyses were performed for all samples. The prevalence of thalassemia in 289 Tay women was 15.6% (gene frequency 0.078) for α 0 -thalassemia (α 0 -thal), 10.0% (gene frequency 0.050) for α + -thal, 7.3% (gene frequency 0.036) for β-thalassemia (β-thal), 2.4% (gene frequency 0.012) for Hb Constant Spring [Hb CS; α142, Term→Gln, T AA> C AA (α2), HBA2 : c.427T>C] and 1.7% (gene frequency 0.009) for Hb E [β26(B8)Glu→Lys, G AG> A AG; HBB : c.79G>A]. Further analysis of β-globin gene abnormalities identified four mutations including codons 41/42 (-TCTT) ( HBB : c.126&#95;129delCTTT), codon 17 (A>T) ( HBB : c.52A>T), codons 71/72 (+A) ( HBB : c.216&#95;217insA), and -28 (A>G) ( HBB : c.78A>G). The results hint at the remarkably high frequencies of severe forms of thalassemia that indicate a serious public health problem requiring further exploration, and most probably, also intervention within the country.

Background: The objective of the study was to describe a formula based on hemoglobin (Hb)A2 and HbF levels for differentiation of homozygous HbE and HbE-β-thalassemia., Methods: A total of 1256 subjects suspected for homozygous HbE or HbE-β0-thalassemia were recruited at the ongoing thalassemia screening program at Khon Kaen University, Thailand. Hb analysis was done using capillary electrophoresis. Genotyping was based on DNA analysis. An arbitrary formula based on HbA2 and HbF was developed statistically for differentiation of the two conditions. Validation was carried out prospectively on another 139 subjects encountered at routine laboratory., Results: Among 1256 subjects, Hb and DNA analyses identified cases with homozygous HbE (n=1076, 85.7%), HbE-β0-thalassemia (n=140, 11.1%), HbE-δβ0-thalassemia (n=30, 2.4%) and unknown HbE-related disorder (n=10, 0.8%). An inverse correlation between the amounts of HbA2 and HbF in HbE-β0-thalassemia was observed. With differences in the amounts of HbA2 and HbF between the groups, an arbitrary score (7.3 HbA2+HbF) was developed where score above 60 indicated HbE-β0-thalassemia. Application of this score on another 139 subjects showed accurate prediction of HbE-β0-thalassemia with 100% sensitivity, 96.5% specificity, 85.7% positive predictive value and 100% negative predictive value. Successful application onto couples at risk was demonstrated., Conclusions: An established score should prove useful in the differentiation of homozygous HbE and HbE-β0-thalassemia in routine setting and lead to a significant reduction in number of referring cases for molecular testing.

Hemoglobin Bart's hydrops fetalis (homozygous α 0 -thalassemia) is the most severe form of thalassemia in the Southeast Asian population. Fetuses with this disorder almost always die in utero or shortly after birth. Screening of α 0 -thalassemia carrier is therefore crucial. Currently, diagnosis of α 0 -thalassemia genes is done by DNA-based analysis which relies on DNA extraction. We have developed a simple screening format based on whole blood PCR assay. The method was validated on 198 specimens and the results show 100% concordance with a conventional gap-PCR on DNA specimens. The protocol could also be applied to amniotic fluid specimens in prenatal diagnostic testing. The assay developed should facilitate carrier screening and prenatal diagnosis of Hb Bart's hydrops fetalis syndrome in the region., (© 2018 by the Association of Clinical Scientists, Inc.)

Background: Severe thalassemia diseases are a major health problem in Southeast Asia. In Cambodia, there has never been a significant program for prevention or control of severe thalassemia. We, therefore, studied the effect of a health education program on severe thalassemia prevention and control in Phnom Penh, Cambodia., Methods: A quasi-experimental study in several communities around Phnom Penh was done. The respective intervention and control group comprised 124 and 117 people, between 18 and 40 years of age, male and female. Pre- and post-tests using a validated and reliable questionnaire were performed in the intervention group and one test was done in the control group. A health education program was organized to give important information to the intervention group and, at the end of the process, to the control group. The outcomes were evaluations of their knowledge and attitude vis-à-vis severe thalassemia prevention and control, and participating in thalassemia screening., Results: Among participants in the intervention group, 105 (84.7%) considered undergoing blood screening vs. 65 (55.6%) in the control group ( p -value < 0.001). In the intervention group, the respective mean scores for knowledge and attitude to a prevention and control program for severe thalassemia before and after health education were 2.6 VS 6.5 ( p -value < 0.001) and 4.6 VS 6.5 ( p -value < 0.001)., Conclusions: The intention to undergo screening was significantly higher in the intervention group than the control group. Knowledge and attitude towards prevention and control of severe thalassemia was significantly improved in the intervention group. Health education clearly heightens awareness and improves consideration of screening for prevention and control of severe thalassemia., Competing Interests: KC is a Cambodian master degree student studying Medical Science at the Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.The Ethics Committee for Human Research of Khon Kaen University (HE591135) and the National Ethics Committee for Health Research, Cambodia (224NECHR) reviewed and approved the study. Getting a blood test was voluntary. Every participant signed informed consent before participating in the research.Not applicableThe authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Haemoglobin (Hb) E is the most common Hb variant in Asia where its gene frequency approaches 0.3 in some areas. We studied genetic background of Hb E genes among Southeast Asian populations. This study examined β-globin gene haplotypes linked to haemoglobin E (Hb E) in diverse groups of Southeast Asian populations. The study was conducted on southern Thai (22 alleles), Cambodian (84 alleles), Laotian (120 alleles), Vietnamese (87 alleles) and Burmese (one allele) subjects. Results were compared with those of previous studies in northeast Thailand, the Yunnan of China, West India and Europe. Ten different haplotypes were observed. The four most common haplotypes were haplotypes 1 (- + - + + + -) and 2 (+ - - - - + -) on chromosomes with framework 2 and haplotypes 6 (- + - + + - +) and 7 (+ - - - - - +) on chromosomes with framework 3 variety. Phylogenetic analysis indicated that haplotype 1 is a relatively recent haplotype found in all populations, whereas haplotype 6 is found predominately in Cambodians. The results indicate that at least two genetic origins of Hb E are responsible for the high prevalence and spread of Hb E among Southeast Asian populations.

α 0 -thalassemia of SEA deletion (- SEA ) is common among Southeast Asian and Chinese. Using haplotype and phylogenetic analyses, we examined the origin of this defect in Southeast Asian populations. Study was done on both normal and α 0 -thalassemia alleles in 3 ethnic groups including 96 Thai, 52 Laotian and 21 Cambodian. Five SNPs encompassing the (- SEA ) including (rs3760053 T>G), (rs1211375 A>C), (rs3918352 A>G), (rs1203974 A>G) and (rs11248914 C>T) were examined using high-resolution melting assays. It was found that 94.0% of Thai, 100% of Laotian and 100% of Cambodian α 0 -thalassemia alleles were linked to the same haplotype: the haplotype H4 (AAGC), representing an Asian specific origin. An G allele of the (rs3760053) was found to be in strong linkage disequilibrium with the α 0 -thalassemia allele in these populations. A multiplex PCR assay was developed to detect simultaneously the (- SEA ) allele and genotyping of a linked (rs3760053) to improve accuracy of prenatal diagnosis of α 0 -thalassemia. Application of this multiplex PCR assay for routine prenatal diagnosis of α 0 -thalassemia in 12 families revealed a 100% concordant result with conventional gap-PCR assay. Therefore, a single genetic origin is responsible for the spread and high prevalence of the (- SEA ) in the region. The multiplex PCR assay developed should provide a double-check PCR system for more accurate diagnosis and allow the monitoring of possible maternal contamination at prenatal diagnosis of this important genetic disorder.

Thalassemia is a genetic condition that can result in long and expensive treatments, and severe thalassemia may lead to death if left untreated. Couples contributing two genes for thalassemia place their children at particular risk for severe thalassemia. Gene frequency of thalassemia varies in Vietnam, but presents remarkably high levels among some ethnic minority groups. Limited information about thalassemia frequency makes prevention and control of thalassemia difficult. This study aimed to determine gene frequency of certain types of thalassemia among 390 women of reproductive age of the Ta-Oi ethnic minority. Hemoglobin and DNA analyses were carried out to diagnose thalassemia and hemoglobinopathies. Of the total participants, 56.1% (95% CI = 51.1-61.1) carried thalassemia genes. A remarkably high frequency of hemoglobin Constant Spring (Hb CS) of 23.8% (95% CI = 19.7-28.4) was noted. The frequency of α + -thalassemia (-3.7 kb deletion) was 26.4% (95% CI = 22.1-31.1), while hemoglobin E (Hb E) and hemoglobin Paksé (Hb Ps) were identified at frequencies of 14.6 (95% CI = 11.2-18.5) and 2.6% (95% CI = 1.4-5.0), respectively. Further analysis of α-globin gene haplotype revealed the same Hb CS haplotype (+ - M + + -) as of the Co-Tu minority, a neighboring minority of the Ta-Oi, indicating that these two minorities may share the same ancestors. This information will be helpful for further studies in population genetics, as well as the development prevention and control program in the region.

Introduction: Thalassemia screening program has been implemented for years in Southeast Asia, but no external quality assessment program has been established. We have developed and initiated the proficiency testing (PT) program for the first time in Thailand with the aim to assess the screening performance of laboratory staff and their competency in interpretation of the screening results., Materials and Methods: Three PT cycles per year were organized. From the first to the third cycle of the PT scheme, a total number of participant laboratories increased from 59 to 67. In each cycle, 2 PT items (assigned as blood samples of the couple) were provided. Performance evaluation was based on the accuracy of screening results, i.e . mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and the dichlorophenolindophenol (DCIP) test for haemoglobin E, including the competency in interpretation of screening results and assessment of foetal risk. Performance was assessed by comparing the participants' result against the assigned value., Results: Of all 3 cycles, most laboratories reported acceptable MCV and MCH values. From the first to the third cycle, incorrect DCIP test and misinterpretation rates were decreased while incorrect risk assessment varied by cycle to cycle. Combining the accuracy of thalassemia screening and the competency in interpretation and risk assessment, approximately half of participants showed excellent performance., Conclusion: Improved performance observed in many laboratories reflects the achievement and benefit of the PT program which should be regularly provided., Competing Interests: Potential conflict of interest: None declared.

This community-based study investigated anemia prevalence and certain hematologic features and their possible relationships to thalassemia and iron deficiency (ID) in a population of older people in Northeastern Thailand. Participants included 319 apparently healthy individuals ranging in age from 60 to 98 years, whose current health status was assessed by means of personal interviews. Blood samples were also collected to determine the following parameters: red blood cell indices, serum ferritin, C-reactive protein, hemoglobin profiles, and the α0-thalassemia gene. Based upon established WHO criteria, the overall prevalence of anemia was found to be 47.7%, increasing from 39% within the age group of 60-70 years to 68% in those >80 years. Factors considered to be significant contributors to anemia were classified as ID (3.6%), thalassemia (56.2%), and "unknown" (40.1%). Overall, only 2.4% of participants exhibited any ID. Hematologic changes appear to correlate with age. Our findings provide not only baseline information, potentially useful for implementing appropriate control measures, but also an enhanced awareness and understanding of the factors contributing to anemia among the elderly in the region., (© 2017 S. Karger AG, Basel.)