Prenatal diagnostic errors in hemoglobin Bart's hydrops fetalis caused by rare genetic interactions of α-thalassemia.

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.

A large cohort of Hb H disease in northeast Thailand: A molecular revisited, diverse genetic interactions and identification of a novel mutation.

Background And Aims: To update the molecular characteristics of α-thalassemia in northeast Thailand, the molecular basis and genetic interactions of Hb H disease were examined in a large cohort of patients.

Materials And Methods: A study was done on 1,170 subjects with Hb H disease and various genetic interactions encountered during 2009-2023. Hb and DNA analyses were carried out.

A large cohort of deletional high hemoglobin F determinants in Thailand: A molecular revisited and identification of a novel mutation.

Background And Aims: High hemoglobin F determinants can be classified into hereditary persistence of fetal hemoglobin (HPFH) and δβ-thalassemia with different phenotype. We report the molecular basis and hematological features in a large cohort of deletional high Hb F determinants in Thailand.

Materials And Methods: Subjects (n = 28,177) encountered during 2015-2022 were reviewed, and those with phenotypically suspected of having high Hb F determinants were selected.

Molecular and haematological characterisation of haemolytic anaemia associated with biallelic KLF1 mutations: a case series.

Aims: Krüppel-like factor 1 (KLF1) is an erythroid-specific transcription factor playing an important role in erythropoiesis and haemoglobin (Hb) switching. Biallelic KLF1 mutations can cause haemolytic anaemia with thalassaemia-like syndromes but are rarely reported. We explore the KLF1 mutations in Thai subjects with unexplainable haemolytic anaemia.

Molecular basis of non-deletional HPFH in Thailand and identification of two novel mutations at the binding sites of CCAAT and GATA-1 transcription factors.

High Hb F determinants are genetic defects associated with increased expression of hemoglobin F in adult life, classified as deletional and non-deletional forms. We report the first description of non-deletional hereditary persistence of fetal hemoglobin (HFPH) in Thailand. Study was done on 388 subjects suspected of non-deletional HPFH with elevated Hb F expression.

Anemia in an ethnic minority group in lower northern Thailand: A community-based study investigating the prevalence in relation to inherited hemoglobin disorders and iron deficiency.

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.

Prospective screening for δ-hemoglobinopathies associated with decreased hemoglobin A levels or hemoglobin A variants: A single center experience.

Background: δ-hemoglobinopathies may lead to misdiagnosis of several thalassemia syndromes especially β-thalassaemia carrier, it is important to evaluate the δ-globin gene defects in areas with high prevalence of globin gene disorders. We describe a prospective screening for δ-hemoglobinopathies in a routine setting in Thailand.

Methods: Study was done on a cohort of 8,471 subjects referred for thalassemia screening, 317 (3.

Molecular basis of a high Hb A/Hb F-thalassemia trait: a retrospective analysis, genotype-phenotype interaction, diagnostic implication, and identification of a novel interaction with -globin gene triplication.

Background: -thalassemia deletion removing 5´-globin promoter usually presents phenotype with high hemoglobin (Hb) A and Hb F levels. We report the molecular characteristics and phenotype-genotype correlation in a large cohort of the -thalassemia with 3.4 kb deletion.

The association of growth differentiation factor-15 levels and osteoporosis in patients with thalassemia.

Background: Ineffective erythropoiesis (IE) is a significant risk factor for osteoporosis in individuals with thalassemia. Growth differentiation factor-15 (GDF15), a biomarker of IE, was found to be elevated in thalassemia patients. This study aimed to examine the association between GDF15 levels and osteoporosis in patients with thalassemia.

Frequency of unnecessary prenatal diagnosis of hemoglobinopathies: A large retrospective analysis and implication to improvement of the control program.

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.

Hemoglobin EE disease in young Laotian children: Hematologic features and the contributions of genetic variations to Hb F expression.

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.

FLT3 Gene Mutations in Acute Myeloid Leukemia Patients in Northeast Thailand.

BACKGROUND Mutations in the FLT3 gene are associated with acute myeloid leukemia (AML). FLT3 mutations have been identified in approximately 30% of de novo AML patients, particularly those with typical karyotype and inferior prognosis. Therefore, we examined the frequencies of an internal tandem duplication (ITD) and missense mutations of the FLT3 gene and their associated clinical characteristics in patients with AML in northeast Thailand.

Anemia, iron deficiency, and thalassemia among the Thai population inhabiting at the Thailand-Lao PDR-Cambodia triangle.

Anemia is a major public health problem in many areas of Southeast Asia. Ascertaining anemia and defining its underlying causes is essential for providing appropriate care, management, and establishment of a control program. Limited studies on these have been carried out on people living at the borders of Thailand, Lao PDR, and Cambodia.

Phosphatidylserine-exposed red blood cells and ineffective erythropoiesis biomarkers in patients with thalassemia.

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.

Five Variable Number of Tandem Repeats Loci (D17S5, APOB, TPO Intron 10, IL-1α Intron 6, and CIAS1) in Thais and Application in the Prenatal Diagnostic Laboratory.

Prenatal diagnosis of genetic disease requires DNA analysis of fetal tissue of a responsible gene. Accurate diagnosis is useful for the appropriate management of pregnancy. However, maternal contamination of fetal specimens poses a high preanalytical risk of prenatal misdiagnosis.

Loop-mediated isothermal amplification (LAMP) colorimetric phenol red assay for rapid identification of α0-thalassemia: Application to population screening and prenatal diagnosis.

Background: Identification of α0-thalassemia (SEA and THAI deletions) is essential in preventing and controlling of severe thalassemia diseases. We have developed the LAMP colorimetric assays for the detection of these two thalassemia defects and validated them in population screening and prenatal diagnosis.

Methods: Three LAMP colorimetric assays specific for α0-thalassemia (SEA deletion), α0-thalassemia (THAI deletion) and normal DNA sequence were developed.

α-thalassemia in affected fetuses with hemoglobin E-β-thalassemia disease in a high-risk population in Thailand.

Objectives: A co-inheritance of α-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-thalassemia in an affected fetus is therefore valuable.

Diagnostic value of fetal hemoglobin Bart's for evaluation of fetal α-thalassemia syndromes: application to prenatal characterization of fetal anemia caused by undiagnosed α-hemoglobinopathy.

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.

Generation of a single-tube quality control material for hemoglobin and DNA analyses of hemoglobinopathies.

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.

Genetic and non-genetic factors affecting hemoglobin A expression in a large cohort of Thai individuals: implication for population screening for thalassemia.

Objective: Increased hemoglobin (Hb) A level is an important diagnostic marker for β-thalassemia carrier screening. The level of Hb A is also useful for differentiating several thalassemia syndromes. We have examined data bases for reduced Hb A expression in a large cohort of Thai subjects.

Direct PCR assays without DNA extraction for rapid detection of hemoglobin Constant Spring and Pakse' genes: application for carrier screening and prenatal diagnosis.

Hemoglobin Constant Spring (Hb CS) and Hb Pakse' (PS) are the common non-deletional α-thalassemia found in Thailand. These two variants can cause severe thalassemia syndromes, especially in fetus and neonate. Molecular diagnosis is the only confirmatory method because Hb CS and Hb PS are usually missed by routine screening and Hb analysis.

Results from 8 years of the proficiency testing program for diagnosis of hemoglobinopathies under the prevention and control program of thalassemia in Thailand.

Introduction: Hemoglobin (Hb) analysis is a key testing for diagnosis of hemoglobinopathies. Accurate analysis, interpretation of results, and genetic risk assessment are important. We report on 8 years of the proficiency testing (PT) program for hemoglobinopathies in Thailand.

δ-Hemoglobinopathies in Thailand: screening, molecular basis, genotype-phenotype interaction, and implication for prevention and control of thalassemia.

The δ-globin gene defects are clinically silent but interaction with β-thalassemia can lead to a misdiagnosis of β-thalassemia carrier. We report an extensive molecular characterization of δ-hemoglobinopathies in Thailand. Study was done on 32,108 subjects, encountered at the thalassemia screening.

Direct Amplification of Whole Blood and Amniotic Fluid Specimens for Prenatal and Postnatal Diagnosis of Hb E-β 0-Thalassemia Diseases.

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.