Congenital Dyserythropoietic Anemia Type II With Myelofibrosis in an Adult Patient: A Report of a Rare Case With a Brief Review.

Congenital dyserythropoietic anemias (CDAs) are rare hereditary disorders, of which type II CDA is the most common. Mutations in the SEC23B gene located on chromosome 20 result in this autosomal recessive disorder. In this case report, we present a case of CDA II with unique biopsy findings being detected via genetic testing. A female aged 30 years presented with major complaints of pallor weakness and easy fatiguability since childhood. The patient gave a history of 25 units of blood transfusion, the majority of which were transfused during pregnancy, followed by regular transfusions thereafter. On examination, all her vitals were in the normal range. Pallor, frontal bossing, and malocclusion of teeth were noted. Her laboratory workup showed the following: hemoglobin (Hb): 3.7 g/dl; mean corpuscular volume: 83 fl; mean corpuscular Hb: 29 g/dl; mean corpuscular Hb concentration: 34.9 g/dl; red cell distribution width: 30.4%; reticulocyte count (RC): 6.2%; corrected RC: 1.3%; lactate dehydrogenase: 441 IU/L; direct Coombs test/indirect Coombs test: negative; serum iron: 242 microgram/dl; transferrin saturation: 96.08%; ferritin: 1,880 ng/ml; and normal high-performance liquid chromatography and eosin-5'-maleimide binding test. The peripheral blood film showed normocytic normochromic anemia with anisopoikilocytosis in the form of a few spherocytes. No immature cells were seen. After obtaining the patient's consent, we performed a hereditary hemolytic anemia gene analysis test, which showed homozygous missense variation in exon 12 of the SEC23B gene. The bone marrow examination showed hyperplasia in the erythroid series with dyserythropoiesis, and surprisingly, myelofibrosis grade I-II (WHO 2017) was also observed on biopsy. Patients with CDA type II generally present with variable degrees of anemia along with pallor, icterus, splenomegaly, gallstones, and iron overload. In our case, the diagnosis of CDA type II was made at an adult age. Also, evidence of myelofibrosis was noted in our case, making it worth reporting. The use of a hereditary hemolytic anemia gene analysis panel test came as a rescue for its exact diagnosis. This case report emphasizes the role of molecular genetic testing for early and accurate diagnosis, which, in turn, could help in appropriate treatment planning and proper genetic counseling. The prevalence of CDA type II is still vaguely known; hence, extensive workup of persistent anemias and proper follow-up would be beneficial.

Identification of a novel splice variant in SEC23B gene in a patient with concomitant presence of congenital dyserythropoietic anemia II and Gilbert's syndrome.

BACKGROUND: Congenital dyserythropoietic anemia Ⅱ (CDA Ⅱ) is a rare inherited disorder of defective erythropoiesis caused by SEC23B gene mutation. CDA Ⅱ is often misdiagnosed as a more common type of clinically related anemia, or it remains undiagnosed due to phenotypic variability caused by the coexistence of inherited liver diseases, including Gilbert's syndrome (GS) and hereditary hemochromatosis. METHODS: We describe the case of a boy with genetically undetermined severe hemolytic anemia, hepatosplenomegaly, and gallstones whose diagnosis was achieved by targeted next generation sequencing. RESULTS: Molecular analysis revealed a maternally inherited novel intronic variant and a paternally inherited missense variant, c.[994-3C > T];[1831C > T] in the SEC23B gene, confirming diagnosis of CDA Ⅱ. cDNA analysis verified that the splice acceptor site variant results in two mutant transcripts, one with an exon 9 skip and one in which exons 9 and 10 are deleted. SEC23B mRNA levels in the patient were lower than those in healthy controls. The patient was also homozygous for the UGT1A1*6 allele, consistent with GS. CONCLUSION: Identification of the novel splice variant in this study further expands the spectrum of known SEC23B gene mutations. Molecular genetic approaches can lead to accurate diagnosis and management of CDA Ⅱ patients, particularly for those with GS coexisting.

Congenital dyserythropoietic anemia type II in a newborn with a novel compound heterozygous mutation in the SEC23B: a case report and review of the literature.

Congenital dyserythropoietic anemia type II (CDA II) refers to a group of extremely rare heterozygous disorders characterized by ineffective erythropoiesis and morphological abnormalities of erythrocytes and bone marrow erythroblasts. Six types of CDA with differing heterogenous genetic mutations have been identified to date. Due to the genetic and clinical heterogeneity of CDA, accurate diagnosis can be very challenging, especially with the clinical overlap observed between CDA and other dyserythropoietic diseases. A 1-month-old infant girl, born to a non-consanguineous family, presented with severe normocytic anemia that required transfusions every 2 to 3 weeks since birth, as well as jaundice. Whole exome sequencing revealed a novel compound heterozygosity in the SEC23B gene, thus establishing the diagnosis of CDA II. Analysis by multiple bioinformatics tools predicted that the mutant proteins were deleterious. Here, we report a novel variation in SEC23B that extends the mutation spectrum of SEC23B in the diagnosis of CDA II.

New Cases and Mutations in SEC23B Gene Causing Congenital Dyserythropoietic Anemia Type II.

Congenital dyserythropoietic anemia type II (CDA II) is an inherited autosomal recessive blood disorder which belongs to the wide group of ineffective erythropoiesis conditions. It is characterized by mild to severe normocytic anemia, jaundice, and splenomegaly owing to the hemolytic component. This often leads to liver iron overload and gallstones. CDA II is caused by biallelic mutations in the SEC23B gene. In this study, we report 9 new CDA II cases and identify 16 pathogenic variants, 6 of which are novel. The newly reported variants in SEC23B include three missenses (p.Thr445Arg, p.Tyr579Cys, and p.Arg701His), one frameshift (p.Asp693GlyfsTer2), and two splicing variants (c.1512-2A>G, and the complex intronic variant c.1512-3delinsTT linked to c.1512-16_1512-7delACTCTGGAAT in the same allele). Computational analyses of the missense variants indicated a loss of key residue interactions within the beta sheet and the helical and gelsolin domains, respectively. Analysis of SEC23B protein levels done in patient-derived lymphoblastoid cell lines (LCLs) showed a significant decrease in SEC23B protein expression, in the absence of SEC23A compensation. Reduced SEC23B mRNA expression was only detected in two probands carrying nonsense and frameshift variants; the remaining patients showed either higher gene expression levels or no expression changes at all. The skipping of exons 13 and 14 in the newly reported complex variant c.1512-3delinsTT/c.1512-16_1512-7delACTCTGGAAT results in a shorter protein isoform, as assessed by RT-PCR followed by Sanger sequencing. In this work, we summarize a comprehensive spectrum of SEC23B variants, describe nine new CDA II cases accounting for six previously unreported variants, and discuss innovative therapeutic approaches for CDA II.

The unfolded protein response transducer IRE1α promotes reticulophagy in podocytes.

Glomerular diseases involving podocyte/glomerular epithelial cell (GEC) injury feature protein misfolding and endoplasmic reticulum (ER) stress. Inositol-requiring enzyme 1α (IRE1α) mediates chaperone production and autophagy during ER stress. We examined the role of IRE1α in selective autophagy of the ER (reticulophagy). Control and IRE1α knockout (KO) GECs were incubated with tunicamycin to induce ER stress and subjected to proteomic analysis. This showed IRE1α-dependent upregulation of secretory pathway mediators, including the coat protein complex II component Sec23B. Tunicamycin enhanced expression of Sec23B and the reticulophagy adaptor reticulon-3-long (RTN3L) in control, but not IRE1α KO GECs. Knockdown of Sec23B reduced autophagosome formation in response to ER stress. Tunicamycin stimulated colocalization of autophagosomes with Sec23B and RTN3L in an IRE1α-dependent manner. Similarly, during ER stress, glomerular α5 collagen IV colocalized with RTN3L and autophagosomes. Degradation of RTN3L and collagen IV increased in response to tunicamycin, and the turnover was blocked by deletion of IRE1α; thus, the IRE1α pathway promotes RTN3L-mediated reticulophagy and collagen IV may be an IRE1α-dependent reticulophagy substrate. In experimental glomerulonephritis, expression of Sec23B, RTN3L, and LC3-II increased in glomeruli of control mice, but not in podocyte-specific IRE1α KO littermates. In conclusion, during ER stress, IRE1α redirects a subset of Sec23B-positive vesicles to deliver RTN3L-coated ER fragments to autophagosomes. Reticulophagy is a novel outcome of the IRE1α pathway in podocytes and may play a cytoprotective role in glomerular diseases.

SEC23B Loss-of-Function Suppresses Hepcidin Expression by Impairing Glycosylation Pathway in Human Hepatic Cells.

Biallelic pathogenic variants in the SEC23B gene cause congenital dyserythropoietic anemia type II (CDA II), a rare hereditary disorder hallmarked by ineffective erythropoiesis, hemolysis, erythroblast morphological abnormalities, and hypo-glycosylation of some red blood cell membrane proteins. Abnormalities in SEC23B, which encodes the homonymous cytoplasmic COPII (coat protein complex II) component, disturb the endoplasmic reticulum to Golgi trafficking and affect different glycosylation pathways. The most harmful complication of CDA II is the severe iron overload. Within our case series (28 CDA II patients), approximately 36% of them exhibit severe iron overload despite mild degree of anemia and slightly increased levels of ERFE (the only erythroid regulator of hepcidin suppression). Thus, we hypothesized a direct role of SEC23B loss-of-function in the pathomechanism of hepatic iron overload. We established a hepatic cell line, HuH7, stably silenced for SEC23B. In silenced cells, we observed significant alterations of the iron status, due to both the alteration in BMP/SMADs pathway effectors and a reduced capability to sense BMP6 stimulus. We demonstrated that the loss-of-function of SEC23B is responsible of the impairment in glycosylation of the membrane proteins involved in the activation of the BMP/SMADs pathway with subsequent hepcidin suppression. Most of these data were confirmed in another hepatic cell line, HepG2, stably silenced for SEC23B. Our findings suggested that the pathogenic mechanism of iron overload in CDA II is associated to both ineffective erythropoiesis and to a specific involvement of SEC23B pathogenic variants at hepatic level. Finally, we demonstrated the ability of SEC23B paralog, i.e., SEC23A, to rescue the hepcidin suppression, highlighting the functional overlap between the two SEC23 paralogs in human hepatic cells.

Compound heterozygosity for two novel mutations of the SEC23B gene in congenital dyserythropoietic anemia type II.

Congenital dyserythropoietic anemia type II (CDA II), a rare genetic disorder, results from SEC23B gene mutations according to previous studies. Here, we present a case of CDA II involving two novel pathogenic mutations of SEC23B that have not previously been reported. The patient suffered from jaundice, tea-colored urine, and weakness. Laboratory data indicated moderately decreased hemoglobin, iron overload, and abnormal erythroblast morphology. Therefore, a diagnosis of CDA II was considered. Peripheral blood samples were used to perform whole exome sequencing, and the results showed compound heterozygosity of the SEC23B gene with the following mutations: c.1162T>A (p.F388I) and c.1603delC (p.R535del). The mutant proteins were predicted to be deleterious and resulted in decreased structural stability. PyMOL software was used to analyze the structural change caused by the p.F388I missense mutation, and the results indicated a deficiency in π-π interactions. In conclusion, our report extends the mutation spectrum of SEC23B in the diagnosis of CDA II.

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.

[New mutation site of SEC23B gene in type â ¡ congenital erythrocythememia anemia: one case report and literatures review].

Objective: To enrich the gene mutation sites and accumulate treatment experience of congenital dyserythropoietic anemia (CDA) type Ⅱ by reporting one case of CDA patient with new mutation site of SEC23B and was successfully treated by homozygous allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The mutation within SEC23B gene in a child case with the reduced hemoglobin for more than 3 months, and his family were analyzed in combination with literatures review. Results: A 3-day 5-month female child was admitted due to "decreasing hemoglobin for more than 3 months" , blood routine test showed HGB 44 g/L, positive for acid hemolysis test (Ham test) . Bone marrow showed that the proportion of erythroid line was 69%, mainly middle and late juvenile erythrocytes, binuclear and odd nucleated erythrocytes could be observed, and nuclear fragmentation and nuclear budding could be seen occasionally in nucleated erythrocytes, transmission electron microscopy disclosed that bone marrow harbored the typical double-layer membrane structure of nuclear erythrocytes. There were two unreported new mutation sites in the SEC23B gene, including 1504 G>C/wt and c. 2254-2255 insert A/wt. The two mutations were derived from the father and mother of the child respectively. At the late stage, the child was successfully treated with allo-HSCT, the original mutation turned negative. Conclusion: This study reported the mutation type of SEC23B gene insertion for the first time in China. Allo-HSCT could be utilized as a treatment for CDA.

New mutation site of SEC23B gene in type Ⅱ congenital erythrocythememia anemia: one case report and literatures review / 中华血液学杂志

Objective@#To enrich the gene mutation sites and accumulate treatment experience of congenital dyserythropoietic anemia (CDA) type Ⅱ by reporting one case of CDA patient with new mutation site of SEC23B and was successfully treated by homozygous allogeneic hematopoietic stem cell transplantation (allo-HSCT) .@*Methods@#The mutation within SEC23B gene in a child case with the reduced hemoglobin for more than 3 months, and his family were analyzed in combination with literatures review.@*Results@#A 3-day 5-month female child was admitted due to "decreasing hemoglobin for more than 3 months" , blood routine test showed HGB 44 g/L, positive for acid hemolysis test (Ham test) . Bone marrow showed that the proportion of erythroid line was 69%, mainly middle and late juvenile erythrocytes, binuclear and odd nucleated erythrocytes could be observed, and nuclear fragmentation and nuclear budding could be seen occasionally in nucleated erythrocytes, transmission electron microscopy disclosed that bone marrow harbored the typical double-layer membrane structure of nuclear erythrocytes. There were two unreported new mutation sites in the SEC23B gene, including 1504 G>C/wt and c. 2254-2255 insert A/wt. The two mutations were derived from the father and mother of the child respectively. At the late stage, the child was successfully treated with allo-HSCT, the original mutation turned negative.@*Conclusion@#This study reported the mutation type of SEC23B gene insertion for the first time in China. Allo-HSCT could be utilized as a treatment for CDA.

New mutation site of SEC23B gene in type Ⅱ congenital erythrocythememia anemia: one case report and literatures review / 中华血液学杂志

Objective: To enrich the gene mutation sites and accumulate treatment experience of congenital dyserythropoietic anemia (CDA) type Ⅱ by reporting one case of CDA patient with new mutation site of SEC23B and was successfully treated by homozygous allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The mutation within SEC23B gene in a child case with the reduced hemoglobin for more than 3 months, and his family were analyzed in combination with literatures review. Results: A 3-day 5-month female child was admitted due to "decreasing hemoglobin for more than 3 months" , blood routine test showed HGB 44 g/L, positive for acid hemolysis test (Ham test) . Bone marrow showed that the proportion of erythroid line was 69%, mainly middle and late juvenile erythrocytes, binuclear and odd nucleated erythrocytes could be observed, and nuclear fragmentation and nuclear budding could be seen occasionally in nucleated erythrocytes, transmission electron microscopy disclosed that bone marrow harbored the typical double-layer membrane structure of nuclear erythrocytes. There were two unreported new mutation sites in the SEC23B gene, including 1504 G>C/wt and c. 2254-2255 insert A/wt. The two mutations were derived from the father and mother of the child respectively. At the late stage, the child was successfully treated with allo-HSCT, the original mutation turned negative. Conclusion: This study reported the mutation type of SEC23B gene insertion for the first time in China. Allo-HSCT could be utilized as a treatment for CDA.

Clinical and genetic features of congenital dyserythropoietic anemia (CDA).

INTRODUCTION: Congenital dyserythropoietic anemias (CDA) are characterized by hyporegenerative anemia with inadequate reticulocyte values, ineffective erythropoiesis, and hemolysis. Distinctive morphology of bone marrow erythroblasts and identification of causative genes allow classification into 4 types caused by variants in CDAN1, c15orf41, SEC23B, KIF23, and KLF1 genes. OBJECTIVE: Identify pathogenic variants in CDA patients. METHODS: Massive parallel sequencing with a targeted gene panel, Sanger sequencing, Comparative Genome Hybridization (CGH), and in silico predictive analysis of pathogenicity. RESULTS: Pathogenic variants were found in 21 of 53 patients studied from 44 unrelated families. Six variants were found in CDAN1: two reported, p.Arg714Trp and p.Arg725Trp and, four novel, p.Arg623Trp, p.Arg946Trp, p.Phe1125Ser and p.Ser1227Gly. Twelve variants were found in SEC23B: seven reported, p.Arg14Trp, p.Glu109Lys, p.Arg217Ter, c.835-2A>G, p.Arg535Ter, p.Arg550Ter and p.Arg718Ter and, five novel, p.Val164Leu, p.Arg190Gln, p.Gln521Ter, p.Arg546Trp, and p.Arg611Gln. The variant p.Glu325Lys in KLF1 was found in one patient and p.Tyr365Cys in ALAS2 in an other. Moreover, we identified genomic rearrangements by CGH in some SEC23B-monoallelic patients. CONCLUSIONS: New technologies for genetic studies will help to find variants in other genes, in addition to those known, that contribute to or modulate the CDA phenotype or support the correct diagnosis.

Identification of CDAN1, C15ORF41 and SEC23B mutations in Chinese patients affected by congenital dyserythropoietic anemia.

Congenital dyserythropoietic anaemias (CDAs) are a group of rare haematological disorders characterized by ineffective erythropoiesis and dyserythropoiesis and reduced numbers of red cells, often with an abnormal morphology. Pathogenic defects in CDAN1, C15ORF41, SEC23B, KIF23, KLF1 and GATA1 genes have been identified in CDAs patients. In this study, we described 13 unrelated Chinese CDAs patients and identified 21 mutations, including 5 novel mutations in CDAN1 gene, and 5 novel mutations in SEC23B gene. Additionally, we predicted the molecular consequence of these missense mutations with Polymorphism Phenotyping v2 (Polyphen), Sorting Intolerant From Tolerant (SIFT), MutPred (http://mutpred1.mutdb.org/) and Protein Variation Effect Analyzer (Provean, http://provean.jcvi.org/seq_submit.php) and analyzed the conservation of the mutated amino acid among proteins from several mammalian species.

Epigenetic disruption of miR-130a promotes prostate cancer by targeting SEC23B and DEPDC1.

MicroRNAs (miRNAs) are small, non-coding RNAs that mediate post-transcriptional gene silencing, fine tuning gene expression. In an initial screen, miRNAs were found to be globally down-regulated in prostate cancer (PCa) cell lines and primary tumours. Exposure of PCa cell lines to a demethylating agent, 5-Aza-CdR resulted in an increase in the expression levels of miRNAs in general. Using stringent filtering criteria miR-130a was identified as the most promising candidate and selected for validation analyses in our patient series. Down-regulation of miR-130a was associated with promoter hypermethylation. MiR-130a methylation levels discriminated PCa from non-malignant tissues (AUC = 0.956), and urine samples revealed high specificity for non-invasive detection of patients with PCa (AUC = 0.89). Additionally, repressive histone marks were also found in the promoter of miR-130a. Over-expression of miR-130a in PCa cells reduced cell viability and invasion capability, and increased apoptosis. Putative targets of miR-130a were assessed by microarray expression profiling and DEPD1C and SEC23B were selected for validation. Silencing of both genes resembled the effect of over-expressing miR-130a in PCa cells. Our data indicate that miR-130a is an epigenetically regulated miRNA involved in regulation of key molecular and phenotypic features of prostate carcinogenesis, acting as a tumour suppressor miRNA.

Diagnosis and Management of Congenital Dyserythropoietic Anaemia Type II in a Secundigravida.

Congenital dyserythropoietic anaemias (CDAs) are very rare, heterogeneous hereditary red blood cell disorders characterized by ineffective erythropoiesis, erythroblast morphological abnormalities, haemolysis, and hypoglycosylation of red-blood-cell membrane proteins and lipids. There are four types (I-IV) of the disease identified, and all of them are associated with abnormal maturation and division of erythroid precursors. We report the management of a rare case of CDA type II diagnosed in a 26-year-old pregnant woman.

Congenital erythropoietic porphyria linked to GATA1-R216W mutation: challenges for diagnosis.

Congenital erythropoietic porphyria (CEP) is a rare genetic disease that is characterized by a severe cutaneous photosensitivity causing unrecoverable deformities, chronic hemolytic anemia requiring blood transfusion program, and by fatal systemic complications. A correct and early diagnosis is required to develop a management plan that is appropriate to the patient's needs. Recently only one case of X-linked CEP had been reported, describing the trans-acting GATA1-R216W mutation. Here, we have characterized two novel X-linked CEP patients, both with misleading hematological phenotypes that include dyserythropoietic anemia, thrombocytopenia, and hereditary persistence of fetal hemoglobin. We compare the previously reported case to ours and propose a diagnostic paradigm for this variant of CEP. Finally, a correlation between phenotype variability and the presence of modifier mutations in loci related to disease-causing gene is described.

Successful hematopoietic stem cell transplantation in a patient with congenital dyserythropoietic anemia type II.

CDA are a group of inherited, rare diseases that are characterized by dyserythropoiesis and ineffective erythropoiesis associated with transfusion dependency in approximately 10% of cases. For these latter patients, the only curative treatment is HSCT. There are very limited data on HSCT experience in this rare disease. Herein, we report a five-yr six-month-old girl with compound heterozygous mutations in SEC23B gene, who was diagnosed to have CDA type II and underwent successful HSCT from her matched sibling donor.