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25 result(s) for "Morado, Marta"
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The role of genetic testing in accurate diagnosis of X-linked sideroblastic anemia: novel ALAS2 mutations and the impact of X-chromosome inactivation
X-linked sideroblastic anemia (XLSA) is a hereditary disorder affecting heme biosynthesis, caused by mutations in the ALAS2 gene, which encodes the erythroid-specific enzyme 5-aminolevulinate synthase. This enzyme, which requires pyridoxal 5’-phosphate (PLP) as a cofactor, catalyzes the first and rate-limiting step of heme synthesis in erythroid cells. XLSA is characterized by hypochromic microcytic anemia and ring sideroblasts in bone marrow, with most patients showing variable degrees of response to pyridoxine supplementation; however, female carriers of ALAS2 mutations often present a distinct clinical phenotype. A comprehensive review of the literature reveals over 100 distinct ALAS2 mutations linked to XLSA in more than 240 families. Here, we report seven new patients (four female cases) initially diagnosed with various conditions, later confirmed to have X-linked Sideroblastic Anemia due to ALAS2 mutations through genetic analysis. Among these, five represent novel ALAS2 mutations, including the first ever reported stop-loss mutation in ALAS2 associated with XLSA rather than X-linked dominant protoporphyria (XLDPP). Computational modelling of six reported cases revealed that four mutations significantly impact protein structure, conformation and cofactor interaction, consistent with our enzymatic assays demonstrating reduced ALAS2 activity. Furthermore, X-chromosome studies in female probands revealed a pronounced skewing of X-chromosome, which may provide an explanation for their distinct clinical manifestations in females.
Study of Adult and Pediatric Spanish Patients with Cryptogenic Splenomegaly and Splenectomy
Introduction: The differential diagnosis of splenomegaly is a complex process that encompasses a wide variety of diseases. Moreover, it is not always standardized and lacks a definitive consensus on which tests should be performed and in what order. Gaucher disease (GD) and acid sphingomyelinase deficiency (ASMD) are lysosomal diseases (LD) that present with splenomegaly, the diagnosis of which requires a high index of suspicion and specific biochemical and genetic techniques. The aim of the project for the education and diagnosis of Gaucher disease and acid sphingomyelinase deficiency (PREDIGA) was to conduct educational training alongside an observational, multicenter, ambispective, cross-sectional, single-cohort study among patients having an enlarged spleen or undergone splenectomy to further assess these subjects to exclude two lysosomal diseases, namely GD and ASMD. Methods: Using dried blood spot (DBS) testing, we identified patients with abnormally low values of the enzymes glucocerebrosidase and acid sphingomyelinase, who then underwent sequencing of the GBA1 and SPMD1 genes, respectively. The study involved 34 hospitals and 52 medical specialists. Results: We identified 220 patients (208 adults and 12 children under 18 years) with cryptogenic splenomegaly or who had undergone splenectomy (12 patients) without having reached a diagnosis. The median age was 11 years (interquartile range [IQR] 3–16) in the pediatric population and 51 years (IQR 38–65) in the adult population. Lower-than-normal enzyme values were detected in 19 DBSs, confirming eight positive cases, which corresponded to six patients with GD and two with ASMD. The rest of the DBSs with low enzyme activity were not genetically confirmed (58%). We determined that lysosomal diseases accounted for 3.6% of cryptogenic splenomegaly/splenectomy cases in our setting: 2.7% were GD and 0.9% ASMD, in a ratio of 1 ASMD patient to every 3 GD patients. Lyso-GL1 values in patients with GD were elevated in all but one individual, corresponding to a child diagnosed at 4 months old. The variants detected in the GBA1 gene were consistent with the most frequent variants found in Spain. Discussion/Conclusion: The development and implementation of this protocol for the education and diagnosis of cryptogenic splenomegaly/splenectomy, even in asymptomatic patients, constitutes a comprehensive, simple, rapid, and effective screening method for the diagnosis of GD and ASMD.
Mitapivat versus Placebo for Pyruvate Kinase Deficiency
Pyruvate kinase deficiency, the most common genetic lesion in the glycolytic pathway, leads to chronic hemolytic anemia. Mitapivat, an oral agent, can activate some mutant enzymes and restore red-cell ATP generation. In this trial, hemoglobin levels increased from baseline by 1.5 g per deciliter or more at 24 weeks in 40% of the patients with pyruvate kinase deficiency who received mitapivat.
Case Report: Durable remission of intraocular mantle cell lymphoma after CD19 CAR-T therapy
Mantle cell lymphoma (MCL) is an aggressive B-cell neoplasm with poor prognosis in refractory relapse. Intraocular (vitreoretinal) involvement is extremely rare and represents a diagnostic and therapeutic challenge due to the immune-privileged status of the eye and the risk of central nervous system (CNS) dissemination. Ocular relapse in mantle cell lymphoma has rarely been described, and evidence on the use of CAR-T therapy in this setting is lacking. We report the case of a 61-year-old man with stage IV-B MCL diagnosed in 2018, who experienced multiple relapses and developed intraocular infiltration confirmed by flow cytometric immunophenotyping of vitreous fluid in 2024. After bridging therapy with intravitreal methotrexate, the patient received CD19-directed CAR-T therapy with brexucabtagene autoleucel (Brexucel) as fifth-line treatment, achieving sustained complete metabolic remission with no ocular or systemic relapse after 19 months of follow-up. This case highlights the diagnostic value of flow cytometry in intraocular lymphomas and supports the expanding role of CAR-T therapy in refractory MCL with atypical sanctuary site involvement.
Rabbit antithymocyte globulin versus horse antithymocyte globulin for treatment of acquired aplastic anemia: a retrospective analysis
Studies comparing rabbit antithymocyte globulin (rATG) and horse ATG (hATG) in patients with aplastic anemia (AA) have shown conflicting results. These studies included fewer than 60 subjects in the rATG arm with relatively short follow-up. A total of 169 patients treated with rATG and 62 treated with hATG were included in this retrospective analysis, across 33 centers. Patients were treated with rATG or hATG plus cyclosporine A. Over half were classified, as having severe AA (SAA) or very severe AA (VSAA), and the mean follow-up was 45 months. There was no significant difference detected in cumulative response to treatment or survival between the rATG and hATG groups. The response to treatment was 63 % in the rATG group versus 66 % in the hATG group at 3 months. By 12 months, this pattern had reversed, and 84 % of rATG patients had responded to treatment versus 76 % in the hATG group (n.s.). Early mortality due to infection tended to be higher with rATG compared to hATG (n.s). rATG and hATG would seem to be therapeutically equivalent in SAA and VSAA. However, patients treated with rATG may take longer to respond than those treated with hATG and may also require more active prevention of early infections.
Women with Gaucher Disease
Gaucher disease is an inherited disorder in which there is a deficiency of the enzyme glucocerebrosidase, which leads to the accumulation of glucosylceramide. Although much scientific evidence is now available, there is still limited data on the impact on the different life stages of women with this disease. Among other alterations, a delay in menarche has been described, although it has not been related to fertility problems. Menorrhagia is relatively frequent, being related to the presence of thrombocytopenia, thrombocytopathies or coagulation disorders. On the other hand, pregnancy planning is an increasingly frequent concern. All patients should undergo genetic counseling, and it is important to monitor the appearance or worsening of organomegaly, bone and hematologic abnormalities to establish clinical and therapeutic recommendations. Management during the puerperium will depend on the evolution of gestation, and, during the lactation period, the potential appearance of bone complications should be assessed. An early onset of menopause, compared to the general population, has also been described, which may accelerate the development of osteopenia. Finally, although the usual screening protocols for neoplasms are currently being performed, it is recommended to watch for early signs of liver or renal neoplasms when examining the results of imaging tests performed during evaluations for this disease.
Synergistic Activity of Deguelin and Fludarabine in Cells from Chronic Lymphocytic Leukemia Patients and in the New Zealand Black Murine Model
B-cell chronic lymphocytic leukemia (CLL) remains an incurable disease, and despite the improvement achieved by therapeutic regimes developed over the last years still a subset of patients face a rather poor prognosis and will eventually relapse and become refractory to therapy. The natural rotenoid deguelin has been shown to induce apoptosis in several cancer cells and cell lines, including primary human CLL cells, and to act as a chemopreventive agent in animal models of induced carcinogenesis. In this work, we show that deguelin induces apoptosis in vitro in primary human CLL cells and in CLL-like cells from the New Zealand Black (NZB) mouse strain. In both of them, deguelin dowregulates AKT, NFκB and several downstream antiapoptotic proteins (XIAP, cIAP, BCL2, BCL-XL and survivin), activating the mitochondrial pathway of apoptosis. Moreover, deguelin inhibits stromal cell-mediated c-Myc upregulation and resistance to fludarabine, increasing fludarabine induced DNA damage. We further show that deguelin has activity in vivo against NZB CLL-like cells in an experimental model of CLL in young NZB mice transplanted with spleen cells from aged NZB mice with lymphoproliferation. Moreover, the combination of deguelin and fludarabine in this model prolonged the survival of transplanted mice at doses of both compounds that were ineffective when administered individually. These results suggest deguelin could have potential for the treatment of human CLL.
Early detection of lysosomal diseases by screening of cases of idiopathic splenomegaly and/or thrombocytopenia with a next‐generation sequencing gene panel
Lysosomal diseases (LD) are a group of about 70 rare hereditary disorders (combined incidence 1:5000) in which diverse lysosomal functions are impaired, impacting multiple organs and systems. The first clinical signs and symptoms are usually unspecific and shared by hundreds of other disorders. Diagnosis of LD traditionally relies on performing specific enzymatic assays, if available, upon clinical suspicion of the disorder. However, the combination of the insidious onset of LD and the lack of awareness on these rare diseases among medical personnel results in undesirable diagnostic delays, with unchecked disease progression, appearance of complications and a worsened prognosis. We tested the usefulness of a next‐generation sequencing‐based gene panel for quick, early detection of LD among cases of idiopathic splenomegaly and/or thrombocytopenia, two of the earliest clinical signs observed in most LD. Our 73‐gene panel interrogated 28 genes for LD, 1 biomarker and 44 genes underlying non‐LD differential diagnoses. Among 38 unrelated patients, we elucidated eight cases (21%), five with LD (GM1 gangliosidosis, Sanfilippo disease A and B, Niemann‐Pick disease B, Gaucher disease) and three with non‐LD conditions. Interestingly, we identified three LD patients harboring pathogenic mutations in two LD genes each, which may result in unusual disease presentations and impact treatment. Turnaround time for panel screening and genetic validation was 1 month. Our results underline the usefulness of resequencing gene panels for quick and cost‐effective screening of LDs and disorders sharing with them early clinical signs.
Sideroblastic anemia: functional study of two novel missense mutations in ALAS2
Background X‐linked sideroblastic anemia (XLSA) is a disorder characterized by decreased heme synthesis and mitochondrial iron overload with ringed sideroblasts in bone marrow. XLSA is caused by mutations in the erythroid‐specific gene coding 5‐aminolevulinate synthase (ALAS2). Anemia in XLSA is extremely variable, characteristically microcytic and hypochromic with poikilocytosis, and the red blood cell distribution width is increased and prominent dimorphism of the red cell population. Anemia in XLSA patients responds variably to supplementation with pyridoxine. Methods and Results We report four patients with XLSA and three mutations in ALAS2: c.611G>A (p.Arg204Gln), c.1218G>T (p.Leu406Phe) and c.1499A>G (p.Tyr500Cys). The in silico predictions of three ALAS2 mutations and the functional consequences of two ALAS2 mutations were assessed. We performed in silico analysis of these mutations using ten different softwares, and all of them predicted that the p.Tyr500Cys mutation was deleterious. The in vitro prokaryotic expression showed that the p.Leu406Phe and p.Tyr500Cys mutations reduced the ALAS2 specific activity (SA) to 14% and 7% of the control value, respectively. Conclusion In view of the results obtained in this study, a clear relationship between genotype and phenotype cannot be established; clinical variability or severity of anemia may be influenced by allelic variants in other genes or transcription factors and environmental conditions. The different types of anemia are distinguished by characteristic hematological parameters and cellular morphology. The genetic study allows a more precise diagnosis. We report four cases with sideroblastic anemia with mutations in the 5‐aminolevulinate synthase (ALAS2) gene. The in silico analysis of mutations and the in vitro study to assess functional consequences of the two novel mutations, leads to suggest that novel ALAS2 mutations are responsible of the disease.