Anemia diseritropoyética congénita tipo I: una mirada actualizada de sus bases moleculares, diagnóstico y tratamiento / Congenital dyserythropoietic anemia type I: an updated review about its molecular bases, diagnosis and treatment

Introducción: Las anemias diseritropoyéticas congénitas constituyen un grupo de trastornos hereditarios caracterizados por anemia refractaria, eritropoyesis ineficaz y alteraciones morfológicas de los eritroblastos. La anemia diseritropoyética congénita tipo I es la más frecuente, no obstante, constituye una rara enfermedad con particularidades morfológicas y moleculares. Objetivo: Analizar los aspectos más novedosos en cuanto a la patogenia molecular, el diagnóstico genético y el tratamiento de la anemia diseritropoyética congénita tipo I. Métodos: Se realizó una revisión de la literatura, en inglés y español. Se utilizaron motores de búsqueda como Google académico y Pubmed que permitió el acceso a artículos actualizados del tema. Se hizo un análisis y resumen de la bibliografía revisada. Análisis y síntesis de la información: La anemia diseritropoyética congénita tipo I es una enfermedad hereditaria autosómica recesiva. Se caracteriza por anemia de grado variable, reticulocitopenia, alteraciones morfológicas de la serie roja en la lámina periférica y un número elevado de eritroblastos binucleados conectados por puentes internucleares en el aspirado de médula ósea. Se han identificado múltiples alteraciones moleculares que involucran fundamentalmente a los genes CDAN1 y C15orf41. Las proteínas codificadas por estos genes participan en proceso vitales como el ciclo celular, la reparación del ADN y la transcripción de ARN. Conclusiones: El estudio de las bases moleculares de la anemia diseritropoyética congénita tipo I ha cambiado la perspectiva en el diagnóstico de esta enfermedad. Los protocolos de tratamiento son similares a otras anemias hemolíticas hereditarias aunque se destaca el uso del Interferón-α(AU)

Introduction: Congenital dyserythropoietic anemias belong to a group of hereditary disorders characterized by refractory anemia, ineffective erythropoiesis and morphological alterations of erythroblasts. Congenital dyserythropoietic anemia type I is the most frequent; however, it is a rare disease with morphological and molecular characteristics. Objective: To analyze the most updated aspects regarding molecular pathogenesis, genetic diagnosis and treatment of congenital dyserythropoietic anemia type I. Methods: A review of the literature in English and Spanish was carried out. Search engines such as Google Scholar and Pubmed were used, which allowed access to updated articles on the subject. An analysis and summary of the revised bibliography was carried out. Information analysis and synthesis: Congenital dyserythropoietic anemia type I is an autosomal recessive hereditary disease. It is characterized by anemia of variable degree, reticulocytopenia, morphological alterations of the red series in the peripheral lamina, and high number of binucleated erythroblasts connected by internuclear bridges in the bone marrow aspirate. Multiple molecular alterations have been identified, mainly involving the CDAN1 and C15orf41 genes. The proteins encoded by these genes participate in vital processes, such as the cell cycle, DNA repair, and RNA transcription. Conclusions: The study of the molecular bases of congenital dyserythropoietic anemia type I has changed the perspective concerning the diagnosis of this disease. Treatment protocols are similar to other hereditary hemolytic anemias, although the use of Interferon-α stands out(AU)

Characterization of the interactions between Codanin-1 and C15Orf41, two proteins implicated in congenital dyserythropoietic anemia type I disease.

BACKGROUND: Congenital dyserythropoietic anemia type I (CDA I), is an autosomal recessive disease with macrocytic anemia in which erythroid precursors in the bone marrow exhibit pathognomonic abnormalities including spongy heterochromatin and chromatin bridges. We have shown previously that the gene mutated in CDA I encodes Codanin-1, a ubiquitously expressed and evolutionarily conserved large protein. Recently, an additional etiologic factor for CDA I was reported, C15Orf41, a predicted nuclease. Mutations in both CDAN1 and C15Orf41 genes results in very similar erythroid phenotype. However, the possible relationships between these two etiologic factors is not clear. RESULTS: We demonstrate here that Codanin-1 and C15Orf41 bind to each other, and that Codanin-1 stabilizes C15Orf41. C15Orf41 protein is mainly nuclear and Codanin-1 overexpression shifts it to the cytoplasm. Phylogenetic analyses demonstrated that even though Codanin-1 is an essential protein in mammals, it was lost from several diverse and unrelated animal taxa. Interestingly, C15Orf41 was eliminated in the exact same animal taxa. This is an extreme case of the Phylogenetic Profiling phenomenon, which strongly suggests common pathways for these two proteins. Lastly, as the 3D structure is more conserved through evolution than the protein sequence, we have used the Phyre2 alignment program to find structurally homologous proteins. We found that Codanin-1 is highly similar to CNOT1, a conserved protein which serves as a scaffold for proteins involved in mRNA stability and transcriptional control. CONCLUSIONS: The physical interaction and the stabilization of C15Orf41 by Codanin-1, combined with the phylogenetic co-existence and co-loss of these two proteins during evolution, suggest that the major function of the presumptive scaffold protein, Codanin-1, is to regulate C15Orf41 activities. The similarity between Codanin-1 and CNOT1 suggest that Codanin-1 is involved in RNA metabolism and activity, and opens up a new avenue for the study of the molecular pathways affected in CDAI.

Response to Alpha-Interferon Treatment of the Congenital Dyserythropoietic Anemia type I in Two Sicilian Beta Thalassemia Carriers.

Congenital dyserythropoietic anemia type I (CDAI) is an autosomal recessive inherited haematological disorder associated with moderate-to-severe anemia characterized by ineffective erythropoiesis with distinct morphological abnormalities in erythroid precursors. We present two case of congenital dyserythropoietic anemia type I in two Sicilian patients heterozygous for ß0 39 globin gene cod 39 C > T with marked bone marrow abnormalities, responding to treatment with alpha interferon. The diagnosis was established using routine haematological and biochemical test, light and electron microscopy; molecular analysis of the CDAN1 gene associated to the CDAI disease was performed. The response to the treatment was monitored using the hemoglobin levels, the red cell count, the reticulocyte count and the transfusional requirement. This report points out the usefulness of the treatment with interferon alpha in two Sicilian beta thalassemia carriers, in which the therapy was well tolerated without producing any side effects; in these patients the transfusion requirements after the initiation of interferon therapy decreased.