Congenital dyserythropoietic anemia type IV in the genetic era: A rare neonatal case report of rapid identification with a review of the literature.

Congenital dyserythropoietic anemia type IV (CDAIV) is a rare inherited hematological disorder, presenting with severe anemia due to altered erythropoiesis and hemolysis, with variable needs for recurrent transfusions. We present a case of a transfusion-dependent male newborn who presented at birth with severe hemolytic anemia, and required an intrauterine transfusion. Genetic testing rapidly identified a Kruppel-like factor 1 (KLF1) pathogenic variant (c.973G>A, p.E325K), known to be causative for CDAIV. This case highlights the advantages of next-generation sequencing testing for congenital hemolytic anemia: diagnostic speed, guidance on natural history, and optimized clinical management and anticipatory guidance for parents and clinicians. Additionally, we reviewed the literature for all CDAIV cases.

Congenital dyserythropoietic anemia type I: First report from the Congenital Dyserythropoietic Anemia Registry of North America (CDAR).

Congenital dyserythropoietic anemias (CDAs) are characterized by ineffective erythropoiesis and distinctive erythroblast abnormalities; the diagnosis is often missed or delayed due to significant phenotypic heterogeneity. We established the CDA Registry of North America (CDAR) to study the natural history of CDA and create a biorepository to investigate the pathobiology of this heterogeneous disease. Seven of 47 patients enrolled so far in CDAR have CDA-I due to biallelic CDAN1 mutations. They all presented with perinatal anemia and required transfusions during infancy. Anemia spontaneously improved during infancy in three patients; two became transfusion-independent rapidly after starting interferon-α2; and two remain transfusion-dependent at last follow-up at ages 5 and 30 y.o. One of the transfusion-dependent patients underwent splenectomy at 11 y.o due to misdiagnosis and returned to medical attention at 27 y.o with severe hemolytic anemia and pulmonary hypertension. All patients developed iron overload even without transfusions; four were treated with chelation. Genetic testing allowed for more rapid and accurate diagnosis; the median age of confirmed diagnosis in our cohort was 3 y.o compared to 17.3 y.o historically. In conclusion, CDAR provides an organized research network for multidisciplinary clinical and research collaboration to conduct natural history and biologic studies in CDA.

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)

Congenital dyserythropoietic anemias.

Congenital dyserythropoietic anemias (CDAs) are a heterogeneous group of inherited anemias that affect the normal differentiation-proliferation pathways of the erythroid lineage. They belong to the wide group of ineffective erythropoiesis conditions that mainly result in monolinear cytopenia. CDAs are classified into the 3 major types (I, II, III), plus the transcription factor-related CDAs, and the CDA variants, on the basis of the distinctive morphological, clinical, and genetic features. Next-generation sequencing has revolutionized the field of diagnosis of and research into CDAs, with reduced time to diagnosis, and ameliorated differential diagnosis in terms of identification of new causative/modifier genes and polygenic conditions. The main improvements regarding CDAs have been in the study of iron metabolism in CDAII. The erythroblast-derived hormone erythroferrone specifically inhibits hepcidin production, and its role in the mediation of hepatic iron overload has been dissected out. We discuss here the most recent advances in this field regarding the molecular genetics and pathogenic mechanisms of CDAs, through an analysis of the clinical and molecular classifications, and the complications and clinical management of patients. We summarize also the main cellular and animal models developed to date and the possible future therapies.

Treatment of transfusion-dependent congenital dyserythropoietic anemia Type I patients with pegylated interferon alpha-2a.

OBJECTIVE: Pegylated IFN-α2a has been reported in two case reports as being efficacious in treating CDA-I patients. This study aims to assess its efficacy on a series of CDA-I patients. METHODS: Study sample consisted of seven CDA type 1 transfusion-dependent patients. They received pegylated interferon alpha-2a at an initial dose of 90-180 µg once a week, tapered according to clinical response and side effects. Good response was defined as Hb ≥ 10 g/dL for ≥3 months, partial response was defined as 7 ≤ Hb<10 g/dL for ≥3 months, and no response was defined as HB < 7 g/dL for over 3 months on treatment. Time to response was defined as the time needed to achieve hemoglobin levels ≥ 10 g/dL without transfusion. Patients were evaluated periodically by abdominal ultrasounds to rule out liver adenomas. RESULTS: Five patients (71%) had a good response to treatment. One patient stopped treatment due to side effects. One patient had partial response. One patient, with more severe phenotype and poor compliance, had poor response to treatment. No abnormal findings were found in ultrasound examination. No effect on serum ferritin level could be established. CONCLUSION: Pegylated interferon α2a therapy is efficacious in CDA-I patients with a reasonable safety profile.

Hematopoietic Stem Cell Transplantation in Congenital Dyserythropetic Anemia Type II: A Case Report and Review of the Literature.

Currently, there is no guideline for the treatment of patients with congenital dyserythropoietic anemia (CDA) type II. One approach is to follow-up patients with transfusions, on the basis of individually determined target hemoglobin levels, and iron chelation according to the thalassemia guidelines. In some transfusion-dependent CDA II patients, splenectomy reduces the number of transfusions; however, the only known curative option for CDA II patients is hematopoietic stem cell transplantation (HSCT). Only a few published case reports of allogeneic HSCT in CDA II patients are available. Here, we review the literature and add our data of a CDA II patient who developed transfusion dependence and was cured with HSCT.

Rare Hereditary Hemolytic Anemias: Diagnostic Approach and Considerations in Management.

Hereditary hemolytic anemias (HHAs) comprise a heterogeneous group of anemias caused by mutations in genes coding the globins, red blood cell (RBC) membrane proteins, and RBC enzymes. Congenital dyserythropoietic anemias (CDAs) are rare disorders of erythropoiesis characterized by binucleated and multinucleated erythroblasts in bone marrow. CDAs typically present with a hemolytic phenotype, as the produced RBCs have structural defects and decreased survival and should be considered in the differential of HHAs. This article discusses the clinical presentation, laboratory findings, and management considerations for rare HHAs arising from unstable hemoglobins, RBC hydration defects, the less common RBC enzymopathies, and CDAs.

The pathogenesis, diagnosis and management of congenital dyserythropoietic anaemia type I.

Congenital dyserythropoietic anaemia type I (CDA-I) is one of a heterogeneous group of inherited anaemias characterised by ineffective erythropoiesis. CDA-I is caused by bi-allelic mutations in either CDAN1 or C15orf41 and, to date, 56 causative mutations have been documented. The diagnostic pathway is reviewed and the utility of genetic testing in reducing the time taken to reach an accurate molecular diagnosis and avoiding bone marrow aspiration, where possible, is described. The management of CDA-I patients is discussed, highlighting both general and specific measures which impact on disease progression. The use of interferon alpha and careful management of iron overload are reviewed and suggest the most favourable outcomes are achieved when CDA-I patients are managed with a holistic and multidisciplinary approach. Finally, the current understanding of the molecular and cellular pathogenesis of CDA-I is presented, highlighting critical questions likely to lead to improved therapy for this disease.

Targeted next generation sequencing for the diagnosis of patients with rare congenital anemias.

BACKGROUND: Most patients with anemia are diagnosed through clinical phenotype and basic laboratory testing. Nonetheless, in cases of rare congenital anemias, some patients remain undiagnosed despite undergoing an exhaustive workup. Genetic testing is complicated by the large number of genes involved in rare anemias and the similarities in the clinical presentation of the different syndromes. OBJECTIVE: We aimed to enhance the diagnosis of patients with congenital anemias by using targeted next-generation sequencing. METHODS: Genetic diagnosis was performed by gene capture followed by next-generation sequencing of 76 genes known to cause anemia syndromes. RESULTS: Genetic diagnosis was achieved in 13 out of 21 patients (62%). Six patients were diagnosed with pyruvate kinase deficiency, 4 with dehydrated hereditary stomatocytosis, 2 with sideroblastic anemia, and 1 with CDA type IV. Eight novel mutations were found. In 7 patients, the genetic diagnosis differed from the pretest presumed diagnosis. The mean lag time from presentation to diagnosis was over 13 years. CONCLUSIONS: Targeted next-generation sequencing led to an accurate diagnosis in over 60% of patients with rare anemias. These patients do not need further diagnostic workup. Earlier incorporation of this method into the workup of patients with congenital anemia may improve patients' care and enable genetic counseling.

KLF1 E325K-associated Congenital Dyserythropoietic Anemia Type IV: Insights Into the Variable Clinical Severity.

We identified a child with KLF1-E325K congenital dyserythropoietic anemia type IV who experienced a severe clinical course, fetal anemia, hydrops fetalis, and postnatal transfusion dependence only partially responsive to splenectomy. The child also had complete sex reversal, the cause which remains undetermined. To gain insights into our patient's severe hematologic phenotype, detailed analyses were performed. Erythrocytes from the patient and parents demonstrated functional abnormalities of the erythrocyte membrane, attributed to variants in the α-spectrin gene. Hypomorphic alleles in SEC23B and YARS2 were also identified. We hypothesize that coinheritance of variants in relevant erythrocyte genes contribute to the clinical course in our patient and other E325K-linked congenital dyserythropoietic anemia IV patients with severe clinical phenotypes.

Morbidity and mortality of adult patients with congenital dyserythropoietic anemia type I.

Congenital dyserythropoietic anemia type I (CDAI) is a rare autosomal recessive disease characterized by macrocytic anemia, ineffective erythropoiesis, and secondary hemochromatosis. To better define the natural history of the disease among adult patients, we studied 32 Bedouin patients (median age 34 yr; range 21-60) all carrying the same CDAN1 founder mutation. Follow-up studies included complete blood count, blood chemistry, abdominal ultrasound, echocardiography, and T2*MRI. Main complications were due to anemia and ineffective erythropoiesis [osteoporosis (8/9, 89%), cholelithiasis (21/30, 70%), pulmonary arterial hypertension (PAH) (6/25, 24%)] and iron overload [hypothyroidism (9/24, 38%), and diabetes mellitus (6/32, 19%)]. T2* MRI revealed increased liver iron but no cardiac iron (13/13). Anemia improved in the majority of patients who underwent splenectomy (5/6). Three patients died (9%) at the age of 46-56 due to PAH (1) and sepsis (2). All previously underwent splenectomy. Analyzing both our patients and the 21 patients previously described by Heimpel et al. (Blood 107:334, 2006), we conclude that adults with CDA I suffer significant morbidity and mortality. Careful monitoring of iron overload and prompt iron chelation therapy is mandatory. Due to possible complications and inconsistent response to splenectomy α-interferon, transfusion therapy or stem cell transplantation should be considered as alternatives to this procedure in severely affected patients.

An Unusual Hydrops Fetalis Associated with Compound Heterozygosity for Krüppel-like Factor 1 mutations.

Hydrops fetalis is commonly due to Hb Bart's (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Krüppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart's disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks' gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks' gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.

Diagnosis and management of congenital dyserythropoietic anemias.

Congenital dyserythropoietic anemias (CDAs) are inherited disorders hallmarked by chronic hyporegenerative anemia, relative reticulocytopenia, hemolytic component and iron overload. They represent a subtype of the inherited bone marrow failure syndromes, characterized by impaired differentiation and proliferation of the erythroid lineage. Three classical types were defined by marrow morphology, even if the most recent classification recognized six different genetic types. The pathomechanisms of CDAs are different, but all seem to involve the regulation of DNA replication and cell division. CDAs are often misdiagnosed, since either morphological abnormalities or clinical features can be commonly identified in other clinically-related anemias. However, differential diagnosis is essential for guiding both follow up and management of the patients.