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Alpha-thalassemia is most often caused by large deletions within the α-globin gene cluster which reduce or abolish α-globin chain synthesis. Several common deletions are well described, but atypical structural variants remain underdiagnosed. In this study, we report three novel large heterozygous deletions of the α-globin cluster. The variants were identified in unrelated patients who presented with persistent microcytosis and hypochromia in the absence of iron deficiency or structural hemoglobin variants. A stepwise molecular diagnostic approach was applied. It combined commercial deletion screening assays, Sanger sequencing, Multiplex Ligation-dependent Probe Amplification (MLPA), and targeted Next-Generation Sequencing (NGS) with the Devyser Thalassemia panel. MLPA detected three deletions ranging from ~17 kb to ~360 kb. All involved the critical HS-40 regulatory region and both HBA1 and HBA2 structural genes, consistent with α0-thalassemia alleles. Next-Generation Sequencing confirmed the extent of each deletion and refined their genomic boundaries. Comparative genomic mapping showed that these deletions are distinct from classical variants such as --SEA or --MED, indicating novel structural configurations. Clinically, all patients displayed a carrier phenotype, with normal HbF levels (<1%) and normal or slightly reduced HbA2 values. This study broadens the mutational spectrum of α0-thalassemia and demonstrates the diagnostic value of combining MLPA and NGS in patients with unexplained microcytosis. By enabling accurate distinction from iron-deficiency anemia and other microcytic disorders, these findings have direct translational implications for improving diagnostic precision and genetic counseling in clinical practice.

Alpha-thalassemia is primarily caused by large deletions in the HBA1 and HBA2 genes, but a minority of cases result from non-deletional mutations, including variants in untranslated regions (UTRs) that affect mRNA regulation. The 3′UTR is crucial for post-transcriptional control, influencing mRNA stability, localization, and translation via binding elements for RNA-binding proteins and microRNAs. We describe two patients with persistent microcytosis and normal iron levels. Standard hematological analyses were complemented by high-performance liquid chromatography (HPLC) and capillary electrophoresis to rule out common hemoglobinopathies. Molecular analysis was performed using multiplex PCR and direct sequencing of the HBA1 3′UTR. Patient 1, a 3-year-old Nigerian boy, carried a novel insertion mutation (HBA1:c.*119_120insT) five nucleotides downstream of the transcription termination signal. Patient 2, a 31-year-old Moroccan woman, exhibited a missense variant (HBA1:c.*150C > A) located 40 nucleotides downstream of the TTS. Both variants are located within regulatory regions of the HBA1 3′UTR. In silico analyses suggest disruption of RNA secondary structure, impaired interactions with HuR and AUF1 proteins, altered microRNA binding (e.g., miR-16-5p), and potential interference with polyadenylation signals, resulting in mRNA instability and reduced alpha-globin synthesis. These two novel mutations in the 3′UTR of HBA1 expand the spectrum of non-deletional alpha-thalassemia variants and highlight the importance of regulatory regions in globin gene expression. Their inclusion in routine molecular screening may enhance diagnostic accuracy in cases of unresolved microcytic anemia.

To verify with hematimetric data that the diagnosis and clinical grade of β-TI can be established when a triplication of alpha genes (α anti 3.7) and heterozygous β-thalassemia coexist. Retrospective study in which 73 patients of Caucasian origin participated, who simultaneously showed a triplication or quadruplication of genes α and β-thalassemia.Screening for the most frequent α-thalassemia mutations as well as gene triplication (α anti 3.7) was carried out by multiplex PCR followed by reverse hybridization with a commercial Alpha-Globin StripAssay kit and confirmed by MLPA (Multiplex ligation-dependent probe amplification). The molecular diagnosis of β-thalassemia was carried out by automatic sequencing according to the Sanger method. The genotypes have been classified into three groups according to the number of α globin genes and the severity of the alteration in the β globin gene. All had a mutation in the HBB gene (β0-thalassemia, β+-thalassemia severe, and β+-thalassemia mild). Group I patients who have coherent 6 α genes and groups II and III with 5 α globin genes. In group III, the patients were carriers of mutations affecting the β and δ globin genes. The most significant hematological parameters were hemoglobin levels, MCV, RDW, and the percentage of Hb F. In group I, regardless of the distribution of the 6 α globin genes, homozygous triplication (α /α ) or heterozygous quadruplication (α /αα), the association with heterozygous β-thalassemia results in severe to moderate anemia that may or may not require transfusion therapy, is the severity of the HBB gene mutation that would determine the clinical variation. Group II patients phenotypically behaved like mild thalassemia intermedia, except for one case that presented thalassemic trait because it also presented an associated α-thalassemia (α /-α3.7). Finally, group III patients behaved as a thalassemic trait since all were carriers of mutations that increase the overexpression of γ genes.

Sickle cell disease (SCD) is a monogenic disease with a highly variable phenotype depending on the amount of fetal hemoglobin (HbF), the main modulator. Variation of HbF levels among patients is genetically regulated. HbF determines both the phenotype of the disease and the response to treatment with the main drug used, hydroxyurea. The efforts of the researchers have focused on discovering the genetic factors responsible for HbF variation, mainly describing the haplotypes of the β cluster and single nucleotide polymorphisms (SNPs) at three different loci: BCL11A, HBS1L-MYB, and the β-globin cluster. This study aimed to determine the possible correlation between the number of SNPs and haplotypes with higher HbF levels in a cohort of patients with SCD. A positive association could explain why certain haplotypes, such as Senegal or Arab-Indian, show higher HbF levels and less severe disease. To test this hypothesis, the characterization of haplotypes was performed using the PCR-RFLP technique and genotyping of three SNPs representative of the three loci with the greatest association with HbF variation: I (rs7482144), BCL11A (rs4671393), and HBS1L-MYB (rs9376092). We found more SNPs in haplotypes related to higher HbF than those with less HbF, although only the SNP I (rs7482144) showed a statistically significant association. We found a direct correlation between haplotypes and the number of SNPs. Haplotypes with higher levels of HbF and less severe phenotypes showed a higher number of SNPs. Thus, the Benin and Bantu haplotypes traditionally associated with poor prognosis showed the fewest mutated SNPs.

It has been proposed that the onset of Acquired Thrombotic Thrombocytopenic Purpura (iTTP) is more severe than subsequent relapses; however, existing studies have limitations. We conducted a retrospective observational study to compare analytical and clinical severity of onset and relapse aTTP cases between 2012 and 2023. A total of 370 episodes of aTTP were analyzed, comprising 272 at initial diagnosis and 98 relapses. At onset, analytical parameters indicative of severity (low hemoglobin, low platelet count, and increased LDH) were significantly worse; patients had severe neurological symptoms (p<0.001) and ≥ 3 points in the TMA mortality score (p<0.001). In conclusion, the onset of aTTP is associated with worse analytical parameters and severe neurological involvement.

The locus control region (LCR) is a genetic region that regulates the expression of the β-globin locus (HBB locus). This region is composed of several DNase I hypersensitive sites (HSs) in which the regulatory functions of the LCR may reside. To date, some individuals bearing deletions of several HSs or even the complete LCR have been described. Although the globin genes of the HBB locus are intact, most of these patients suffer thalassemia due to the reduced expression of such genes. The LCR and the HSs forming it have been thoroughly studied in different genetic models. However, seemingly contradictory results are often obtained. Here, we describe the first deletion found in humans exclusively affecting the HS3 element of the LCR. The adult carrying this deletion shows very mild hematological modifications, indicating that HS3 deletion does not severely impair the β-gene expression. Our results also reveal limitations of the murine models when studying the native mouse genes for understanding human diseases like thalassemias.

Thalassemias are the most frequent monogenic disorders around the world and are a serious health problem in areas with a high incidence. Thalassemias are particularly frequent in Mediterranean countries, the Middle East, Africa, the Indian subcontinent, and in the Southeast Asia. Of these, α-thalassemia is inherited as an autosomal recessive disorder. α-thalassemias are due to a deficiency or absence of hemoglobin (Hb) α-chain synthesis and are characterized by microcytic and hypochromic cells anemia and a clinical phenotype varying from nearly asymptomatic to a lethal hemolytic anemia. Compound heterozygotes and some homozygotes have a moderate to severe form of α-thalassemia called HbH disease. Hb Bart’s hydrops fetalis is a lethal form in which no α-globin chain is synthesized. In this study we show a new structural variant of α-chain, Hb Cibeles [alpha 25(B6) Gly → Asp], in heterozygous state, which was undetectable by electrophoretic or chromatographic methods. Hb Cibeles is thus a hyper-unstable hemoglobinopathy. In this new globin chain variant, an apolar amino acid is replaced by a negatively charged amino acid. This change may be responsible for the molecular hyper-instability similar to the mutation in the adjacent residues.

Alpha-thalassemia is primarily caused by large deletions in the HBA1 and HBA2 genes, but a minority of cases result from non-deletional mutations, including variants in untranslated regions (UTRs) that affect mRNA regulation. The 3'UTR is crucial for post-transcriptional control, influencing mRNA stability, localization, and translation via binding elements for RNA-binding proteins and microRNAs. We describe two patients with persistent microcytosis and normal iron levels. Standard hematological analyses were complemented by high-performance liquid chromatography (HPLC) and capillary electrophoresis to rule out common hemoglobinopathies. Molecular analysis was performed using multiplex PCR and direct sequencing of the HBA1 3'UTR. Patient 1, a 3-year-old Nigerian boy, carried a novel insertion mutation (HBA1:c.*119_120insT) five nucleotides downstream of the transcription termination signal. Patient 2, a 31-year-old Moroccan woman, exhibited a missense variant (HBA1:c.*150C > A) located 40 nucleotides downstream of the TTS. Both variants are located within regulatory regions of the HBA1 3'UTR. In silico analyses suggest disruption of RNA secondary structure, impaired interactions with HuR and AUF1 proteins, altered microRNA binding (e.g., miR-16-5p), and potential interference with polyadenylation signals, resulting in mRNA instability and reduced alpha-globin synthesis. These two novel mutations in the 3'UTR of HBA1 expand the spectrum of non-deletional alpha-thalassemia variants and highlight the importance of regulatory regions in globin gene expression. Their inclusion in routine molecular screening may enhance diagnostic accuracy in cases of unresolved microcytic anemia.

Alpha-thalassemia is most often caused by large deletions within the α-globin gene cluster which reduce or abolish α-globin chain synthesis. Several common deletions are well described, but atypical structural variants remain underdiagnosed. In this study, we report three novel large heterozygous deletions of the α-globin cluster. The variants were identified in unrelated patients who presented with persistent microcytosis and hypochromia in the absence of iron deficiency or structural hemoglobin variants. A stepwise molecular diagnostic approach was applied. It combined commercial deletion screening assays, Sanger sequencing, Multiplex Ligation-dependent Probe Amplification (MLPA), and targeted Next-Generation Sequencing (NGS) with the Devyser Thalassemia panel. MLPA detected three deletions ranging from ~17 kb to ~360 kb. All involved the critical HS-40 regulatory region and both HBA1 and HBA2 structural genes, consistent with α[sup.0]-thalassemia alleles. Next-Generation Sequencing confirmed the extent of each deletion and refined their genomic boundaries. Comparative genomic mapping showed that these deletions are distinct from classical variants such as --SEA or --MED, indicating novel structural configurations. Clinically, all patients displayed a carrier phenotype, with normal HbF levels (<1%) and normal or slightly reduced HbA2 values. This study broadens the mutational spectrum of α[sup.0]-thalassemia and demonstrates the diagnostic value of combining MLPA and NGS in patients with unexplained microcytosis. By enabling accurate distinction from iron-deficiency anemia and other microcytic disorders, these findings have direct translational implications for improving diagnostic precision and genetic counseling in clinical practice.