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(1) Background: Thalassemia syndromes are common monogenic disorders that represent a significant global health issue. No systematic epidemiological or molecular investigations on thalassemias in the Croatian population have been reported to date. (2) Methods: This prospective study included 70 children with a presumptive diagnosis of thalassemia and their 42 first-degree relatives. Molecular characterization was performed using direct sequencing and gap-PCR methods. (3) Results: We identified 46 (30 children and 16 first-degree relatives) β-thalassemia heterozygous carriers from 24 unrelated families, carrying eight different mutations and one hemoglobin variant. Five variants account for approximately 85% of all affected β-globin alleles: Hb Lepore-Boston-Washington (32.6%), HBB:c.93-21G>A (19.6%), HBB:c.315+1G>A (13.1%), HBB:c.92+1G>A (10.9%), and HBB:c.92+6T>C (8.7%) variants. (4) Conclusions: β-thalassemia carriers need more detailed genetic profiling since genetic modifiers can significantly impact their phenotype. Our study provides important new insights into the relevance of β-thalassemia heterozygosity in pediatric clinical practice. [ABSTRACT FROM AUTHOR]

The prevalence of thalassemia among the Vietnamese population was studied, and clinical decision support systems (CDSSs) for prenatal screening of thalassemia were created. A cross-sectional study was conducted on pregnant women and their husbands visiting from October 2020 to December 2021. A total of 10,112 medical records of first-time pregnant women and their husbands were collected. CDSS including two different types of systems for prenatal screening for thalassemia (expert system [ES] and four artificial intelligence [AI]-based CDSS) was built. 1,992 cases were used to train and test machine learning (ML) models while 1,555 cases were used for specialized ES evaluation. There were 10 key variables for AI-based CDSS for ML. The four most important features in thalassemia screening were identified. Accuracy of ES and AI-based CDSS was compared. The rate of patients with alpha thalassemia is 10.73% (1,085 patients), the rate of patients with beta-thalassemia is 2.24% (227 patients), and 0.29% (29 patients) of patients carry both alpha-thalassemia and beta-thalassemia gene mutations. ES showed an accuracy of 98.45%. Among AI-based CDSS developed, multilayer perceptron model was the most stable regardless of the training database (accuracy of 98.50% using all features and 97.00% using only the four most important features). AI-based CDSS showed satisfactory results. Further development of such systems is promising with a view to their introduction into clinical practice. [ABSTRACT FROM AUTHOR]

Background: Hemoglobinopathies are the most common inherited diseases in humans resulting from impaired globin chain synthesis of hemoglobin. The progression of thalassemia rates is prevented with prenatal screening methods. Aims: To evaluate the hematological parameters of α- and β-thalassemia and normal fetuses aged 17-25 weeks of gestation. Study Design: A cross-sectional study. Methods: Pregnant women who underwent cordocentesis in the second trimester because of the risk of having a baby with thalassemia were included in the study. Hematological indices and molecular DNA methods were analyzed from the cord blood samples of 129 women who were 17-25 weeks into pregnancy. The HPLC method was used for Hb fraction analysis. Amplification refractory mutation system, restriction enzyme analysis, multiplex polymerase chain reaction, and sequencing methods were used for the molecular analysis. Maternal contamination was eliminated by the short tandem repeat method. Results: In total, 112 of the fetuses carry α- and β-thalassemia heterozygous or homozygous (α: 37, β: 58, mixed: 17) and 17 fetuses had a normal genotype for thalassemia. Significant differences in adult hemoglobin (HbA), fetal hemoglobin (HbF), Hb Barts, MCV, MCH, and RDW were detected in three groups compared with the normal group (p < 0.001, except for RBC, Hb, HCT, and MCHC). Differences in HbF, Hb Barts, MCV, MCH, and RDW were observed in the α-thalassemia groups compared with the normal group (p < 0.001). Among the five β-thalassemia subgroups, only HbA and RDW were different from the normal group (p < 0.001). Conclusion: This study could be a good reference for future studies and prenatal diagnostic applications in emphasizing the importance of changes in the blood parameters of fetuses before molecular genotyping. These hematological data give valuable information to clinicians about the fetus to enlighten families in making appropriate decisions during prenatal diagnosis. [ABSTRACT FROM AUTHOR]

Background and Objectives Thalassemia is the most common monogenic disease worldwide inherited in autosomal recessive manner. Beta-thalassemia is caused by mutations in beta-globin gene. It is characterized by reduction in red blood cell indices including low MCV, low MCH, high RBC count, low HbA1 and high HbA2. Considering these symptoms, finding a relation between erythrocyte indices and kind of mutations can be used as a rapid method in mutation diagnosis and initial screening of carriers. Materials and Methods In this descriptive-analytical study after DNA extraction from 200 beta- thalassemia minors in Khuzestan province by salting out method, we amplified and sequenced beta-globin gene by Sanger sequencing. Finally, we analyzed statistically the beta-globin gene mutations and erythrocyte indices association by SPSS. Results Our results showed that IVSII-1(G > A) is the most common mutation with 22.5% frequency in this population of beta-thalassemia carriers. We found that MCV index variations have a meaningful association with beta-globin gene mutations and the highest mean of MCV (65.4 ± 3.7) was observed in IVSI-110(G > A) mutation. Conclusions The results comply with many other studies performed in this field and can be used for rapid detection of mutation in carrier parents and prenatal diagnosis. [ABSTRACT FROM AUTHOR]

Introduction: Analysis of fetal DNA in at risk couples for thalassemia is performed from fetal trophoblast or amniotic fluid cells. Although these procedures are in common use, the main limitation is essentially due to the late gestation week in which diagnosis is performed. The celomic cavity develops around 4 weeks of pregnancy within the extraembryonic mesoderm and contains embryonic erythroid precursor cells as a source of fetal DNA that can be used to perform invasive prenatal diagnosis. Methods: Celomatic fluids were obtained at 8 weeks of gestation in thirteen women with high‐risk pregnancies. Twelve of these couples were at risk for Hb Lepore disease and β‐thalassemia and one couple represented a rare case in which both parents were carriers of Hb Lepore Boston‐Washington. Fetal cells were isolated by micromanipulator and nested polymerase chain reactions were performed. Results: The analysis was successfully performed in all examined cases. Two fetuses were found to have a compound heterozygosity for β‐thalassemia and Hb Lepore Boston‐Washington, three fetuses were found to be carriers of β‐thalassemia, three fetuses of Hb Lepore, five were found without parental mutations. The genotypic analysis, carried out both by amniocentesis and on abortive tissue or after birth, showed concordance with results obtained on fetal celomic DNA. Conclusion: Our results unequivocally show that fetal DNA can be obtained by nucleated fetal cells present in celomatic fluid and demonstrate for the first time that prenatal diagnosis of β‐thalassemia and Hb Lepore may be feasible in an earlier time of pregnancy than other procedures. [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]

Objective To evaluate the repercussions of recent changes to the cut-offs used in the first screening step of the pre-marital screening programme for thalassaemia prevention in Iran. Methods The profiles of 984 subjects referred to a genetic laboratory, and the tests of 242 parents of children with thalassaemia major were assessed for red blood cell (RBC) indices, haemoglobin (Hb) A2 levels and results of Hb electrophoresis. Results Of 407 suspected thalassaemia minor (STM) cases, 18 proved positive for thalassaemia minor on molecular analysis (18/407, confidence interval 2.6–6.9%). If the revised screening cut-offs had been used to determine who would undergo molecular analysis, two of these cases would not have been identified. Only 4.4% of suspected cases with lower than normal RBC indices (mean corpuscular volume <80 fl and mean corpuscular Hb <27 pg) and HbA2 (<3.5%) were diagnosed with thalassaemia minor. Conclusion The thalassaemia major prevention programme is performed in two separate steps. One step involves the screening of subjects and identification of β-thalassaemia minor, suspected cases for thalassaemia minor (STM), and normal subject groups. The other step concerns the identification of thalassaemia minor in the STM group. Changing the cut-offs at the first screening step does not result in significant improvement from an economic view, and is associated with significant risk at the second screening step. [ABSTRACT FROM AUTHOR]

Objective: Prenatal diagnosis of β-thalassemia carrier couples has helped to prevent bearing affected children. Among 177 couples referred to our laboratory for prenatal diagnosis, 14 mothers had twin pregnancies. Methods: By using direct and indirect methods, we determined their mutations and linkage analysis using polymorphic markers (restriction fragment length polymorphism [RFLP]). Results: It was shown that in five families both fetuses were heterozygote carriers. In another five families, one fetus was normal and the other one was carrier. In two families, one fetus was affected and the other one was heterozygous carrier; in one case one fetus was affected and the other one was homozygote normal. In the last family both fetuses were homozygote normal. If all fetuses were fraternal then one would expect to see seven homozygote normal and the same number affected, and 14 carriers. Conclusion: Our results indicated that at least in cases where both fetuses had identical genotypes, then they may be identical twins. Molecular testing indeed showed that in three cases the twins were identical. Another point is that in three cases, one of the twin fetuses was affected and the other one was either normal or heterozygote in which only the affected fetuses were aborted by the specialist. [ABSTRACT FROM AUTHOR]