Malignant lymphoma in congenital dyserythropoietic anaemia type III

Congenital dyserythropoietic anemia types Ib, II, and III: novel variants in the CDIN1 gene and functional study of a novel variant in the KIF23 gene

Congenital dyserythropoietic anemias (CDA) are disorders characterized by ineffective erythropoiesis and morphological anomalies in erythrocytes and erythroblasts. The purpose of this study is to identify the gene variants in patients diagnosed with CDA. We analyzed five unrelated patients and two siblings with a targeted panel of genes to CDA: CDAN1, CDIN1, SEC23B, KIF23, KLF1, and GATA1 genes. We found three novel variants in the CDIN1 gene (p.Leu136Val, p.Tyr247Cys, and p.Ile273Thr), four known variants in the SEC23B gene (p.Arg14Trp, p.Arg554Ter, p.Asp239Gly, and p.Ser436Leu), and one novel variant in the KIF23 gene (p.Leu945Trpfs*31). The in silico analysis of novel variants predict that they are pathogenic and, the in vitro study confirms the functional impact of the KIF23 variant on the protein location.

Congenital dyserythropoietic anemia type III (CDA III) is caused by a mutation in kinesin family member, KIF23

Haplotype analysis and targeted next-generation resequencing allowed us to identify a mutation in the KIF23 gene and to show its association with an autosomal dominant form of congenital dyserythropoietic anemia type III (CDA III). The region at 15q23 where CDA III was mapped in a large Swedish family was targeted by array-based sequence capture in a female diagnosed with CDA III and her healthy sister. Prioritization of all detected sequence changes revealed 10 variants unique for the CDA III patient. Among those variants, a novel mutation c.2747C>G (p.P916R) was found in KIF23, which encodes mitotic kinesin-like protein 1 (MKLP1). This variant segregates with CDA III in the Swedish and American families but was not found in 356 control individuals. RNA expression of the 2 known splice isoforms of KIF23 as well as a novel one lacking the exons 17 and 18 was detected in a broad range of human tissues. RNA interference-based knock-down and rescue experiments demonstrated that the p.P916R mutation causes cytokinesis failure in HeLa cells, consistent with appearance of large multinucleated erythroblasts in CDA III patients. We conclude that CDA III is caused by a mutation in KIF23/MKLP1, a conserved mitotic kinesin crucial for cytokinesis.

Congenital dyserythropoietic anemia

Congenital dyserythropoietic anemias (CDAs) are a heterogeneous group of rare hereditary disorders of erythropoiesis characterized by morphologic abnormal erythroblasts in the bone marrow. Three types of the disease are known as type I, II and III, and the variant type of CDA and several minor subgroups of CDA have been also reported since the first classification. Recently, responsible genes for type I (CDAN1) and type II (SEC23B) have been identified and the molecular pathogenesis of the disease is currently being explored. Although CDAs rarely transform to myelodysplastic syndrome or leukemia, the disease is important to understand the mechanism of hemopoiesis in humans.

The congenital dyserythropoietic anemias

The congenital dyserythropoietic anemias (CDAs) are a heterogeneous group of hereditary disorders that seem to be restricted to the erythroid lineage. They are characterized by morphologic abnormalities of erythroid precursors in the bone marrow, resulting in ineffective erythropoiesis and a suboptimal reticulocyte response. As with many rare disorders, cases of CDA are often misdiagnosed, which may lead to inappropriate management. In this review, the authors highlight the relevant clinical data together with recent molecular advances that should aid decision making in diagnosis and patient management.

Advances in the understanding of the congenital dyserythropoietic anaemias

The congenital dyserythropoietic anaemias (CDAs) are a heterogeneous group of diseases in which the anaemia is predominantly caused by dyserythropoiesis and marked ineffective erythropoiesis; three major (types I, II and III) and several minor subgroups have been identified. Additional information on the natural history of these conditions, the beneficial role of splenectomy in CDA type II and efficacy of interferon-alpha in type I have recently been reported. A disease gene has been localised to a chromosomal segment in the three major types and in CDA type I, a disease gene has been identified (CDANI). Mutations have been detected in both familial and sporadic cases but the predicted protein structure gives few clues as to its function. In both type I and II, there are cases unlinked to the identified localisations, suggesting genetic heterogeneity.

Sickle cell anemia and hematological neoplasias

Sickle cell disease (SCD) is a congenital hemolytic anemia with various clinical findings. In some cases hematological neoplasias and some solid tumors may accompany this disease but these have rarely been reported. Here we report five cases with SCD and accompanying hematological neoplasias including lymphoblastic lymphoma, multiple myeloma and hairy cell leukemia in four cases with sickle cell trait and one case of Hodgkin' disease in sickle cell anemia. All of the cases except one had no previously diagnosed congenital hemolytic anemia and/or family history. Peripheral blood findings suggestive for an underlying hemolytic anemia were the first step and the most important initial lead in the detection of SCD. Severe musculoskeletal signs during the first presentation was seen in the lymphoma case, residual renal dysfunction after remission of multiple myeloma, and areas of infarction in the spleen in CT scans in the patient with sickle cell anemia were the most interesting findings in these cases. A standard therapeutic approach without any additional toxicity was relevant in all cases. Detailed clinical presentation and outcome of these five cases are documented here and the literature has been reviewed.

Male siblings with dyserythropoiesis, microcephaly and intrauterine growth retardation

Male siblings with intrauterine growth retardation, hydrops, mild liver dysfunction, chronic diarrhoea, failure to thrive and microcephaly are reported. In both patients, the intrauterine growth retardation was detected in the second trimester of pregnancy. Relatively severe early onset neonatal jaundice, microcytosis, anisocytosis and abnormal iron metabolism were also seen. Bone marrow examination in the second sibling showed marked ringed sideroblasts and multilobulated erythroblasts in late developmental stages. The brain was very small with enlarged cerebrospinal fluid space, a reduced number of gyri and a thin cortex. The clinical and laboratory findings in these patients appear to be unique.

Congenital dyserythropoietic anemia type III associated with congenital atrioseptal defect has led to severe cardiac problems in a 32-year-old patient

We report the case of a 32-year-old woman who was admitted at hospital because of ortho-dyspnea, arrhythmia, and paleness. Clinical examination showed continuous arrhythmia, systolic heart murmur, enlargement of spleen and liver, and pathologic hematological parameters, thus indicating an intravasal hemolysis (elevated HBDH, bilirubin, and reticulocytes; reduced hemoglobin and haptoglobin levels), and bone-marrow-smears showed a typical cytomorphology of CDA III. The patient's diagnosis was heart failure caused by mitral valve insufficiency due to congenital atrioseptal defect associated with congenital dyserythropoietic anemia type III (CDA III).

Congenital dyserythropoietic anemias

The congenital dyserythropoietic anemias (CDAs) are an uncommon and heterogeneous group of disorders characterized by markedly ineffective erythropoiesis and, usually, striking dysplastic changes in erythroblasts. Each of the three originally described forms, designated CDA types I to III, is defined by the presence of distinctive morphologic (including ultrastructural) abnormalities in erythroblasts. CDA type II is also characterized by a marked reduction in polylactosamine structures associated with the erythrocyte membrane glycoprotein, band 3 (detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis), and, usually, a positive result on the acidified serum lysis test. The course of CDA is often complicated by cholelithiasis. Even patients who have not had transfusions sometimes develop substantial iron overload. Recent studies have extended our knowledge on the clinical manifestations of CDA types I and III and have revealed the existence of forms of CDA distinct from types I to III. Information is now available on the chromosomal localization of the genes involved in CDA types I and II and in the Swedish cases of CDA type III. A few patients with CDA type I have been treated with interferon-alpha2, with a good response.

Congenital dyserythropoietic anaemias: clinical features, haematological morphology and new biochemical data

Three types of congenital dyserythropoietic anaemia (CDA) were originally identified on the basis of the pattern of dysplastic changes in the erythroblasts and the results of the acidified serum lysis test (Ham test). These were designated CDA types I, II and III. Several other types have been described subsequently and new forms continue to be reported. Some patients with CDA develop iron overload even without repeated blood transfusion and may present with the complications of severe iron overload. Dysmorphic features are seen in some cases, especially of CDA type I. In CDA type II, incomplete processing of N-linked oligosaccharides leads to a marked reduction of polylactosamines associated with band 3 of the red cell membrane. A few cases of CDA type III develop lymphoid neoplasms. Some of the Swedish cases of CDA type III have developed a retinal abnormality characterized by angioid streaks and macular degeneration. The chromosomal localizations of the disease gene in CDA types I and II and in the Swedish family with CDA type III are now known, but the identities of the mutant genes are still unknown. Cases of CDA type I have shown a partial haematological response to interferon-alpha, however the biochemical basis of this response is unclear. An important step in the diagnosis of sporadic cases of CDA is the exclusion of known causes of acquired dyserythropoiesis.