Guidelines for the diagnosis and management of hereditary spherocytosis--2011 update

Influence of diabetes and hypercholesterolemia on laboratory methods for hereditary spherocytosis diagnosis

INTRODUCTION

Hereditary spherocytosis (HS) is characterized by decreased erythrocyte deformability resulting in hemolytic anemia. This is a heterogeneous disease regarding underlying protein deficiency, disease severity, age at diagnosis and clinical course. Although largely considered as pediatric disease, HS could be initially diagnosed also in elder patients as a result of gallstones or splenomegaly fortuitous finding. Concurrently, common adulthood metabolic disorders like diabetes or dyslipidemia are also known to impair RBC rheology and deformability. Therefore, we aimed to investigate if these diseases affect the screening and diagnostic tools used for HS diagnosis.

METHODS

We applied our workflow for HS diagnosis on 95 pathological samples: 29 patients with diabetes, 20 with hypercholesterolemia, 17 with dyslipidemia, 6 with hypertriglyceridemia, 23 with metabolic syndrome (MS). Thus, a total of 73 samples were analyzed by automated reticulocyte analysis, 52 by cryohemolysis test, and 41 by ektacytometry osmoscan analysis as we used two out of the three tests for each individual sample.

RESULTS

Applying our screening algorithm based on automated reticulocyte indices, a total of 4 samples (4.2%): one sample (5%) from the diabetes group and three samples (16.7%) from the MS group, positioned into the HS zone. However, no significant difference was found between any of the pathological groups and the controls for the cryohemolysis test or the osmoscan.

CONCLUSION

While diabetes and hypercholesterolemia are pathologic conditions known to present with decreased erythrocyte deformability and disturbed rheology, their possible concomitant presence with HS would not interfere with the screening and confirmatory laboratory methods.

Disseminated lymph node tuberculosis after splenectomy: an unusual case report in an adolescent

BACKGROUND

Splenectomized patients are at an increased risk for overwhelming post-splenectomy infections typically with encapsulated bacteria. The clinical association between splenectomy and lymph-node tuberculosis is unclear.

CASE PRESENTATION

We describe a rare case of disseminated tuberculous lymphadenitis in an 18-year-old woman with history of splenectomy because of hereditary sherocytosis. She was admitted with enlargement of bilateral-cervical and left-axillary lymph nodes and fever. A diagnosis of probable tuberculosis was made based on the findings of fine-needle aspiration. Histology showed granulomas and extensive caseous necrosis, with the site of puncture located at an enlarged lymph node on the right side. The diagnosis was confirmed via nucleic-acid amplification tests following excisional biopsy of the left axillary lymph node. Disseminated tuberculous lymphadenitis was localized in the bilateral neck, right lung hilum, left sub-axillary region, and mediastinum, as detected from contrast-enhanced computed tomography of the neck.

CONCLUSIONS

Mycobacterium tuberculosis infection should be considered in children and adolescents with extensive enlargement of lymph nodes after splenectomy.

Facilitating EMA binding test performance using fluorescent beads combined with next‐generation sequencing

The eosin‐5′‐maleimide (EMA) binding test is widely used as diagnostic test for hereditary spherocytosis (HS), one of the most common haemolytic disorders in Caucasian populations. We recently described the advantages of replacing the use of healthy control blood samples with fluorescent beads in a modified EMA binding assay. In this study we further explore this novel approach. We performed targeted next‐generation sequencing, modified EMA binding test and osmotic gradient ektacytometry on consecutive individuals referred to our laboratory on the suspicion of HS. In total, 33 of 95 carried a (likely) pathogenic variant, and 24 had variants of uncertain significance (VUS). We identified a total 79 different (likely) pathogenic variants and VUS, including 43 novel mutations. Discarding VUS and recessive mutations in STPA1, we used the occurrence of (likely) pathogenic variants to generate a diagnostic threshold for our modified EMA binding test. Twenty‐one of 23 individuals with non‐SPTA1 (likely) pathogenic variants had EMA ≥ 43.6 AU, which was the optimal threshold in receiver operating characteristic (ROC) analysis. Accuracy was excellent at 93.4% and close to that of osmotic gradient ektacytometry (98.7%). In conclusion, we were able to simplify the EMA‐binding test by using rainbow beads as reference and (likely) pathogenic variants to define an accurate cut‐off value.

The diagnostic protocol for hereditary spherocytosis-2021 update

Background

Hereditary spherocytosis (HS), a commonly encountered hereditary hemolytic disease, is mostly inherited in an autosomal dominant manner. The clinical manifestations in patients with HS show obvious heterogeneity. Moreover, the sensitivity or specificity of some HS diagnostic tests are not ideal and may easily result in misdiagnosis or missed diagnosis in some patients. The objective of this study was to propose a simple and practical diagnostic protocol, which can contribute to the diagnosis of HS and its differential diagnosis with different types of hemolytic anemia such as thalassemia (THAL), autoimmune hemolytic anemia (AIHA), and glucose‐6‐phosphate dehydrogenase (G6PD) deficiency, thus, to provide an alternative simple and reliable method for better clinical diagnosis of HS.

Methods

Through combing our research with existing experimental technologies and studies, we propose a simple and practical protocol for HS diagnosis, which will help clinicians to improve HS diagnosis.

Results

Compared with the existing HS diagnostic protocols, the HS diagnostic protocol we proposed is simpler. In this new protocol, some experimental tests with ideal diagnostic efficiency are added, such as mean reticulocyte volume (MRV), mean sphered cell volume (MSCV), mean corpuscular volume (MCV), in combination with the observation of clinical manifestations, family investigation, routine tests for hemolytic anemia, genetic testing, and other screening tests.

Conclusion

The HS diagnostic protocol we proposed could improve the clinical practice and efficiency of HS diagnosis.

Efficacy of cytochemical tests in gene analysis of hereditary spherocytosis: a case study of six patients with different disease subtypes

OBJECTIVES

In this study, clinical and biochemical methods were utilized to predict the final diagnosis of hereditary spherocytosis (HS), correlate the diagnosis with splenectomy, and examine the usefulness of this approach.

METHODS

We biochemically and cytochemically analysed erythrocyte membrane proteins before making a final HS diagnosis based on gene analysis to compare diagnostic approaches. The clinical features of six patients with various subtypes of HS and symptoms were observed by blood analysis using eosin-5'-maleimide staining, biochemical analysis using sodium dodecyl sulphate - polyacrylamide gel electrophoresis with western blotting, and mass spectrometry. Finally, diagnostic membrane gene analysis was performed.

RESULTS

Five of the six patients showed mild to moderate or severe anaemia, and the other patient was non-anaemic; all six patients showed faint eosin-5'-maleimide staining. In western blotting of erythrocyte membrane proteins, all six patients (three with β-spectrin, two with ankyrin, and one with SLC4A1 anomalies) showed low-molecular-weight peptide fragments, which were confirmed by mass spectrometry in the region corresponding to the band 3 protein. The two patients with an ankyrin gene anomaly exhibited severe anaemia, and two patients with simultaneous SLC4A1, SPTB, and UGT1A1 anomalies exhibited mild anaemia and hyperbilirubinemia.

DISCUSSION

We determined the relationship among clinical features, cytochemical parameters, and gene anomalies in six patients with newly diagnosed HS while referring to previously published cases.

CONCLUSION

These findings reveal a close relationship between clinical features and membrane characteristics in HS, which can facilitate diagnosis and inform treatment.

Identification of a Novel Mutation of β-Spectrin in Hereditary Spherocytosis Using Whole Exome Sequencing

Hereditary spherocytosis (HS), the most commonly inherited hemolytic anemia in northern Europeans, comprises a group of diseases whose heterogeneous genetic basis results in a variable clinical presentation. High-throughput genome sequencing methods have made a leading contribution to the recent progress in research on and diagnostics of inherited diseases and inspired us to apply whole exome sequencing (WES) to identify potential mutations in HS. The data presented here reveal a novel mutation probably responsible for HS in a single Polish family. Patients with clinical evidence of HS (clinical symptoms, hematological data, and EMA test) were enrolled in the study. The examination of the resulting WES data showed a number of polymorphisms in 71 genes associated with known erythrocyte pathologies (including membranopathies, enzymopathies, and hemoglobinopathies). Only a single SPTB gene variant indicated the possible molecular mechanism of the disease in the studied family. The new missense mutation p.C183Y was identified using WES in the SPTB gene, which is most likely the cause of clinical symptoms typical of hereditary spherocytosis (membranopathy) due to structural and functional impairments of human β-spectrin. This mutation allows for a better understanding of the molecular mechanism(s) of one of the membranopathies, hereditary spherocytosis.

Comparison of a modified flow cytometry osmotic fragility test with the classical method for the diagnosis of hereditary spherocytosis

BACKGROUND

Hereditary spherocytosis (HS) is the most common inherited hemolytic anemia. The flow cytometric test using eosin-5'maleimide (EMA) is a well-established diagnostic method. However, in order to improve HS detection, it is recommended that EMA and an osmotic fragility test (OFT) both be performed. OFT is time consuming and labor intensive. We used a flow cytometric (FOFT) adaptation of the classical OFT reported by Yamamoto. We compare the FOFT to the classical OFT including practical data and propose options for simplifying this method.

METHODS

Suspected and known HS patients and controls were tested by the following methods: EMA, OFT, and FOFT including some modifications.

RESULTS

The FOFT method is robust and correlates to loss of red blood cells. OFT and FOFT gave similar results in healthy controls and four HS patients. Normal range for FOFT in 70 adults is shown and can be used as a reference value. Neonates should have their own normal range defined. Overnight sample incubation at 37°C did not add information to the FOFT results.

CONCLUSION

Our modified Yamomoto FOFT can replace the classic OFT as the addition to EMA for the diagnosis of HS. The use of flow cytometry in both these methods requires small sample volume, is reproducible, simpler, and produces results more rapidly.

Cerebrovascular Complications of Anemia

PURPOSE OF THE REVIEW

Anemia has been called the fifth cardiovascular risk factor. It is one of the most prevalent pathologies worldwide. In this article, we aimed to perform a narrative review of the main cerebrovascular complications of anemia and its influence on stroke prognosis.

RECENT FINDINGS

Both hypoproliferative anemia (thalassemia, iron deficiency anemia, etc.) and hyperproliferative anemia (sickle cell disease, paroxysmal nocturnal hemoglobinuria, hereditary spherocytosis, etc.) are associated to cerebrovascular disease ranging from transient ischemic attack to ischemic stroke and hemorrhagic stroke with both intraparenchymal hemorrhage and subarachnoid hemorrhage or cerebral venous thrombosis. Anemia is associated to a worse prognosis in patients with cerebrovascular disease In some cases, like sickle cell disease, pathophysiological mechanisms and therapeutic guidelines are well established, while in others, due to their rarity, there are still lack of robust data. More studies are needed to clarify how the prognosis of stroke patients with anemia could be improved.

Severe Presentation of Congenital Hemolytic Anemias in the Neonatal Age: Diagnostic and Therapeutic Issues

Congenital hemolytic anemias (CHAs) are a group of diseases characterized by premature destruction of erythrocytes as a consequence of intrinsic red blood cells abnormalities. Suggestive features of CHAs are anemia and hemolysis, with high reticulocyte count, unconjugated hyperbilirubinemia, increased lactate dehydrogenase (LDH), and reduced haptoglobin. The peripheral blood smear can help the differential diagnosis. In this review, we discuss the clinical management of severe CHAs presenting early on in the neonatal period. Appropriate knowledge and a high index of suspicion are crucial for a timely differential diagnosis and management. Here, we provide an overview of the most common conditions, such as glucose-6-phosphate dehydrogenase deficiency, pyruvate kinase deficiency, and hereditary spherocytosis. Although rare, congenital dyserythropoietic anemias are included as they may be suspected in early life, while hemoglobinopathies will not be discussed, as they usually manifest at a later age, when fetal hemoglobin (HbF) is replaced by the adult form (HbA).

Hereditary Spherocytosis as an Atypical Presentation of Anemia in Ulcerative Colitis

Anemia is encountered in up to two-thirds of all patients with inflammatory bowel disease (IBD). We are reporting a case of a 9-year-old female with history of very early onset IBD ulcerative colitis, and primary sclerosing cholangitis who was found to have hereditary spherocytosis as the etiology of her anemia. Despite good clinical response to IBD therapy, she continued to have persistent normocytic anemia. Liver biopsy and magnetic resonance cholangiopancreatography for uptrending liver transaminases demonstrated iron deposition which led to a T2-weighted magnetic resonance imaging study that quantified significant iron deposition in her liver and kidneys. Without any history of blood transfusions, these findings were concerning for hereditary hemochromatosis, but the hereditary hemochromatosis gene test was negative. Whole genome sequencing identified a pathogenic de novo variant consistent with hereditary spherocytosis.

Table of Contents Summary

A novel presentation of anemia in inflammatory bowel disease.

Mutational Characteristics of Causative Genes in Chinese Hereditary Spherocytosis Patients: a Report on Fourteen Cases and a Review of the Literature

Background: Hereditary spherocytosis (HS), characterized by the presence of spherocytic red cells in peripheral blood, hemolysis, splenomegaly, jaundice, and gallstones, is a common form of inherited hemolytic anemia (HA). To date, five causative genes associated with HS have been identified, including ANK1, SPTB, SPTA1, SLC4A1, and EPB42.

Methods: Clinically suspected patients with HS or undiagnosed HA from 14 Chinese families were enrolled in this study. We presented the patients’ clinical features and identified the causative gene variants in these patients using whole exome sequencing (WES), with 10 novel and four reported mutations in the ANK1 and SPTB genes (seven mutations in ANK1 and seven in SPTB), individually. Then, we reviewed all available literature on Chinese HS patients from 2000 to 2020 in PubMed and Chinese Journals with genetic results and clinical information, to delineate gene mutation spectrum and potential correlation with phenotypes.

Results: A total of 158 variants (including 144 in previous reports and 14 in this study) indicated that ANK1 (46%) and SPTB (42%) were the most frequently mutated genes in Chinese HS patients, followed by SLC4A1 (11%) and SPTA1 (1%), while no mutations in EPB42 was reported. Most of the mutations in ANK1 and SPTB were nonsense (26/73 in ANK1 and 32/66 in SPTB) and frameshift (20/73 in ANK1 and 15/66 in SPTB), while missense mutations (14/18) accounted for the majority in SLC4A1. The higher mutation frequency of ANK1 was found in its exon 8, 9, 26, and 28. The majority of mutations in SPTB were located in its exon 13, 15, and 18–30, whereas mutations in SLC4A1 were scattered throughout the entire region of the gene.

Conclusion: Our study expanded the mutation spectrum of ANK1 and SPTB. Furthermore, we clarified the mutational characteristics of causative genes by reviewing all available literature on Chinese patients with HS.

Preliminary Study on the Clinical and Genetic Characteristics of Hereditary Spherocytosis in 15 Chinese Children

Objective

To investigate the clinical and genetic characteristics of hereditary spherocythemia (HS) in Chinese children, and to analyze the potential genotypic/phenotypic associations.

Methods

The clinical data and gene test results of children with HS were collected. All patients were diagnosed by gene test results, and the laboratory results were obtained before splenectomy. The data of red blood cell (RBC), hemoglobin (HB), mean red blood cell volume (MCV), mean red blood cell hemoglobin (MCH), mean red blood cell hemoglobin concentration (MCHC), and hematocrit (HCT) were statistically analyzed according to different mutation genes. Statistical methods for comparison between groups Mann–Whitney test analysis, two-terminal p < 0.05 was considered significant difference.

Results

A total of 15 children were enrolled in our hospital, and 14 variants were found (nine variants have not been reported before), including 10 ANK1 mutations (seven ANK1 truncated mutations) and five SPTB mutations. Patients with ANK1 mutations had more severe anemia than those with SPTB mutations (significantly lower RBC, HB, MCHC, and HCT).

Conclusion

This is one of the few studies on the genetic and clinical characteristics of children with HS in China. This study identified the unique genetic and clinical characteristics of Chinese children with HS and analyzed the pathogenic genotype–phenotypic association. The results confirmed that the anemia degree of HS patients caused by ANK1 was more serious than that of patients with SPTB deficiency. However, further study of the correlation between genotype and phenotype requires a larger sample size.

Identification of a De Novoc.1000delA ANK1 mutation associated to hereditary spherocytosis in a neonate with Coombs-negative hemolytic jaundice-case reports and review of the literature

Background

To strengthen the understanding of Hereditary Spherocytosis (HS) and determine the disease-causing mutation present with neonatal jaundice. HS is a hemolytic condition resulting from various erythrocyte membrane defects. Many different mutations result in HS, including mutations in ANK1.

Case presentation

A term neonate presented at ten hours with severe jaundice requiring exchange transfusion. At two months he was hospitalized due to repeated pallor and anemia requiring blood transfusions. Using next-generation sequencing, we discovered the responsible mutation in the proband but not in his parents; a heterozygous nucleotide variation of c.1000delA (p.1334Sfs*6) in ANK1. Thus hereditary spherocytosis was diagnosed.

Conclusions

Genetic detection is an important means of discovering the cause of hemolytic anemia in neonates and infants where routine diagnostic tests are unrevealing. We found a novel de novo mutation, c.1000delA (p.1334Sfs*6) in ANK1 that might account for other cases of HS in the Chinese population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-00912-3.

Successful Splenectomy Management in a Patient With Moderate Factor VII Deficiency and Concomitant Severe Hereditary Spherocytosis

By the advent of the effective therapies for many coagulation diseases and hereditary spherocytosis (HS), patient's survival has been improved significantly; however, if patients are diagnosed late or left untreated, both diseases could ominously be life threatening. Concurrent occurring of factor VII (FVII) deficiency and HS is extremely rare and there is no literature report that explain this condition, thus far. In this study, we confronted a 9-year-old female patient diagnosed with HS and enlarged spleen as a result of this blood disorder. Given to her sever signs and symptoms of splenomegaly, she was candidate for emergent splenectomy. However, assessment of coagulation tests revealed a prolonged prothrombin time, suggesting the moderate FVII deficiency. With a multidisciplinary consultation, we decided to performed total splenectomy with prophylaxis administration of totally 6 doses of active recombinant FVII, initiated 1 hour before surgery and followed until 30 hours postoperation. As a result of cautious undertaken in Mofid Children's Hospital, the patient did not experience any hemostatic defect. Patient is now 14-year-old, generally well-being under regular surveillance of FVII deficiency.

Clinical manifestation and phenotypic analysis of novel gene mutation in 28 Chinese children with hereditary spherocytosis

Purpose

Objective to summarize the clinical features and laboratory findings of 28 Chinese children with hereditary spherocytosis (HS), and analyze these mutations.

Method

Collected and analyzed the clinical data of all children and their parents, and completed the relevant laboratory examinations of all children. Analyzed the sequence of related genes by second‐generation sequencing technology, and verified the suspected mutations by Sanger sequencing method. Analyzed all biological information using the Single Nucleotide Polymorphism database, the 1000 Human Genome Project, and the Exosome Aggregation Consortium.

Result

New mutations were detected in the HS coding region of 28 children. Among them, there were 13 cases (46.4%) with ANK1 mutation, 10 cases (35.7%) with SPTB mutation, three cases (10.7%) with SLC4A1 mutation, and two cases (7.2%) with SPTA1 mutation. All mutations cause amino acid changes in the coding gene, as well as subsequent changes in protein structure or loss of function.

Conclusion

All the newly discovered gene coding region mutation sites detected are the suspected pathogenic causes of the 28 Chinese children. At the same time, the second‐generation gene sequencing technology is an effective means to diagnose HS. Different mutation types and different mutation regions have no significant correlation with the severity of anemia. The novel gene mutation sites in 28 children studied in this paper have not yet been included in the human genome database, dbSNP (v138), or ExAC database. The new gene mutations found in HS children can provide a theoretical basis for further exploring the genetic causes of HS in Chinese children.

Screening tools for hereditary hemolytic anemia: new concepts and strategies

INTRODUCTION

Hereditary hemolytic anemias are a group of rare and heterogeneous disorders due to abnormalities in structure, metabolism, and transport functions of erythrocytes; they may overlap in clinical and hematological features making differential diagnosis difficult, particularly in mild and atypical forms.

AREAS COVERED

In the present review, the main tools currently adopted in routine hematologic investigation for the diagnosis of hereditary hemolytic anemias are described, together with the new diagnostic approaches that are being to be developed in the next future. Available recommendations in this field together with a systematic review through MEDLINE, EMBASE, and PubMED for publications in English from 2000 to 2020 in regards to diagnostic aspects of hereditary hemolytic anemias have been considered.

EXPERT OPINION

The recent development of specific molecules and treatments for hereditary hemolytic anemias and the increased interest in translational research raised the attention on differential diagnosis and the demand for novel diagnostic assays and devices. Automatic blood cell analyzers, omic-approaches including NGS technologies, and development of new automated tools based on artificial neural networks definitely represent the future strategies in this field.

Hereditary spherocytosis overlooked for 7 years in a pediatric patient with β-thalassemia trait and novel compound heterozygous mutations of SPTA1 gene

Objectives: We aimed to determine the clinical and genetic characteristics of a boy diagnosed with the β-thalassemia trait. He also had hereditary spherocytosis (HS) that had been overlooked for 7 years. Methods: Blood samples collected from the proband and his family were assessed by laboratory tests, and next-generation sequencing (NGS) and Sanger sequencing. Results: The β-thalassemia trait was complicated with HS in the proband. Compound heterozygous mutations of the Spectrin Alpha, Erythrocytic 1 (SPTA1) gene, c.83G > A and c.190G > A in the proband were inherited from his mother and father, respectively, and he also had the heterozygous c.126_129delCTTT mutation in the Hemoglobin Subunit Beta (HBB) gene. The c.190G > A mutation has not yet been added to the Human Gene Mutation Database (HGMD®). The heterozygous HBB c.126_129delCTTT mutation was inherited from his mother, and his older brother also had this mutation. Conclusion: Compared with other patients with either HS or β-thalassemia, this proband with both HS and the β-thalassemia trait had very complicated laboratory findings, which resulted in HS being overlooked for 7 years. Genetic testing is invaluable for the differential diagnosis of hereditary anemias with overlapping clinical features.

Open heart surgery in an infant with hereditary spherocytosis and a review of literature

Hemolytic anemia often challenges congenital heart surgery. Hereditary spherocytosis is a rare familial hemolytic anemia. When associated with congenital heart disease, the safe performance of cardiopulmonary bypass becomes a priority. The increased risk of hemolysis during cardiopulmonary bypass could potentially lead to significant secondary organ damage. Till now, only very few reports of successful repair of a congenital heart defect in patients with hereditary spherocytosis have been reported. We report the only case of successful repair of a congenital heart defect in an infant with hereditary spherocytosis.

Characterization of hereditary red blood cell membranopathies using combined targeted next-generation sequencing and osmotic gradient ektacytometry

Hereditary red blood cell (RBC) membranopathies are characterized by mutations in genes encoding skeletal proteins that alter the membrane complex structure. Hereditary spherocytosis (HS) is the most common inherited RBC membranopathy leading to hereditary hemolytic anemia with a worldwide distribution and an estimated prevalence, in Europe, of about 1:2000 individuals. The recent availability of targeted next generation sequencing (t-NGS) and its combination with RBC deformability measured with a laser-assisted optical rotational ektacytometer (LoRRca) has demonstrated to be the most powerful contribution to lower the percentage of hereditary hemolytic anemia undiagnosed cases. In order to know the kind and frequency of RBC membrane mutations in our geographical area (Catalonia) and to better understand their pathophysiology, 42 unrelated, non-transfusion-dependent (NTD) patients with hereditary hemolytic anemia have been studied by combining t-NGS and LoRRca. The osmoscan module of LoRRca provides three rheological profiles that reflect the maximal deformability (EImax), osmotic fragility (Omin), and hydration state (Ohyper) of RBCs and contribute to a better understanding of the contribution RBC rheology to the severity of anemia. From the 42 patients studied, 37 were suspected to be a RBC membrane defect due to phenotypic characteristics and abnormal RBC morphology and, from these, in 31 patients (83.8% of cases) the mutation was identified by t-NGS. No definite diagnosis was achieved in 11 patients (26.2% of cases), including 6 out of 37 cases, with suspected membranopathy, and 5 with unclassifiable HHA. In all these undiagnosed patients, the existence of hemoglobinopathy and/or enzymopathy was ruled out by conventional methods.

Beta-Spectrin Deletion Responsible for Hereditary Spherocytosis: When New Technologies Are Not the Key to Success

Hereditary spherocytosis arises from alterations in the genes encoding red blood cell membrane proteins. Although its diagnosis is mostly clinical, recent advances in next-generation sequencing (NGS) technologies have allowed for a faster cost-effective gene-based diagnosis. We report the case of a boy with spherocytic anemia and development delay in whom a de novo 2.84-Mb deletion at chromosome 14 including SPTB (ß-spectrin gene) was identified by array-based comparative genomic hybridization. This alteration, consistent with de novo spherocytosis, was missed by a NGS gene panel. When associated with other symptoms, especially neurologic, NGS may not be appropriate to genetically diagnose spherocytic anemia.

Red cell membrane protein abnormalities as defined by sds-page among patients with anemia in a West African region hospital practice

Background:

Erythrocytes require an ability to deform and withstand shear stress while negotiating microcirculation. These properties are largely due to their excess surface area per volume and the characteristics of the membrane’s protein. Deficiencies of these proteins are associated with chronic hemolysis.

Methods:

This was a cross-sectional study aimed at determining the prevalence of red cell membrane protein abnormalities as determined by sodium dodecyl sulphate polyacrilamide gel electrophoresis (SDS-PAGE) among patients with anemia attending the outpatient clinics of the hospital.

Results:

A total of 823 participants were recruited into the study with a mean age of 34±14 years. There were 410 (49.8%) participants with hematocrit ≥ 36% and 413 with hematocrit ≤ 35.9% of which 192 participants (23.3%) had abnormal red cell indices. Following SDS-PAGE, 21 (10.9%) of the 192 participants had deficient PAGE tracing. Abnormal spectrin band was observed in 17 (81%) of the 21 participants. The hematocrit was significantly lower while the reticulocyte count and red cell distribution width were higher in participants with red cell membrane abnormalities.

Conclusion:

One in ten patients with mild anemia and abnormal red cell indices in clinical practice may be having hereditary red cell membrane protein defect. Presence of raised reticulocyte count, family history of mild anemia, increased red cell distribution width and red cell morphology may be used to screen for membrane deficiency.

A novel SPTB gene mutation in neonatal hereditary spherocytosis: A case report

The aim of the present study was to enhance the understanding of the diagnosis and treatment of neonatal hereditary spherocytosis (HS). Gene sequencing and analysis was performed for the crucial splicing signals on the exons and introns of the 302 known pathogenic genes [including ANK1, SPTAN1, SPTA1, EPB42, SLC4A1, and SPTB] that are associated with this genetic deficiency of erythrocytes. A 26-day-old female presented with jaundice, anemia, an increased count in peripheral blood reticulocyte and spherocytes and a positive acidified glycerol hemolysis test. Gene sequencing revealed a novel mutation of c.3737delA (p.Lys1246fs) in the exon 16 of SPTB (14q23|NM_000347.5) gene in the patient and her father. The mutation was a frame-shifting mutation, which may result in the truncation of β-haemoglobin in the erythrocyte membrane can lead to loss of normal function, leading to the occurrence of diseases, including jaundice and hemolytic anemia. For neonates with jaundice and anemia, family history, erythrocyte index and peripheral blood smear findings have been indicated to contribute to the diagnosis of HS. In the current study, gene sequencing was indicated to be helpful for the diagnosis of HS. A novel mutation of SPTB gene was identified, which may be pathogenic via modulating the activity of β-spectrin in the erythrocyte membrane.

Genetic and Clinical Characteristics of Patients With Hereditary Spherocytosis in Hubei Province of China

Hereditary spherocytosis (HS) is an inherited disorder characterized by anemia, splenomegaly, and spherical-shaped erythrocytes, caused by mutations in erythrocyte membrane Protein Genes (ANK1, SPTB, SLC4A1, SPTA1, and EPB42). We investigated molecular spectrum and genotype-phenotype correlation in HS patients in Hubei province, central China. Twenty-three patients with HS were included. A next-generation sequencing (NGS) panel targeting ANK1, SPTB, SLC4A1, SPTA1, and EPB42 genes was used to screen potential variants. Sanger sequencing was applied to validate variants. Of the twenty-three patients, thirteen patients carried ANK1 variants, and ten patients harbored SPTB variants, including ten non-sense, six indel, four splice site, one start-loss, and one missense variant. Four out of twenty-two variants in our study were known, and eighteen variants were novel. Most ANK1 and SPTB variants were indel (5/12) or non-sense (7/10), respectively. Family member analysis in thirteen families showed that six variants were de novo. Variable expressivities were observed in a pair of twins with ANK1 c.341C > T variant, and two unrelated patients both carried ANK1 c.2T > A variant. Genotype-phenotype analysis found no significant difference between ANK1 and SPTB regarding the levels of Hb, RBC, MCV, MCH, and MCHC. However, variants in the ANK1 death domain were associated with lower levels of MCV and MCH compared to other ANK1 domains. In conclusion, NGS is a fast way to provide a molecular HS diagnosis. We also identified unique genetic and clinical characteristics of patients with HS in Hubei Province, China. However, a large sample size is needed to further investigate the genotype-phenotype correlation.

Transfusion support: Considerations in pediatric populations

Over 400,000 units of blood and blood products are transfused to pediatric patients annually, yet only sparse high-quality data exist to guide the preparation and administration of blood products in this population. The direct application of data from studies in adult patients should be undertaken with caution, as there are dissimilarities in the pathology and physiology between adult and pediatric patients. We provide an overview of available evidence in the field of pediatric transfusion medicine, summarizing indications for blood product transfusion, thresholds for transfusion and indications for blood product modifications.

Multiple splenic infarcts: unusual presentation of hereditary spherocytosis associated with acute Epstein-Barr virus infection

A 19-year-old African American woman presented to the emergency department with a history of left upper quadrant pain for a week, associated with nausea, malaise, loss of appetite, subjective fevers and chills. Her family history is significant for thalassemia in her maternal aunt, and hereditary spherocytosis in her brother, sister and cousin. A contrast-enhanced CT scan of the abdomen and pelvis revealed massive splenomegaly and multiple splenic infarcts. On the second day of admission, she developed a fever of 103°F. Further evaluation revealed acute Epstein-Barr virus (EBV) infection and hereditary spherocytosis. Her condition improved after 4 days on piperacillin/tazobactam, intravenous fluids, analgesics and antipyretics. Our case report describes a thorough clinical evaluation of a patient with fever, anaemia, massive splenomegaly and multiple splenic infarcts. It highlights the need for careful interpretation of multiple positive IgM results on viral serological testing that often accompanies acute EBV infections.

Hereditary spherocytosis diagnosed with extremely low glycated hemoglobin compared to plasma glucose levels

Glycated hemoglobin (HbA1c) is an important indicator of glycemic control in patients with diabetes. High-performance liquid chromatography (HPLC) is the most commonly used method for measuring HbA1c levels; as HPLC measures all hemoglobin types, the values can be influenced by hemoglobin variants. Moreover, as HPLC-HbA1c levels are low in some diseases, including hemolytic anemia, it may be difficult to differentiate hemoglobin variants from these diseases based on HPLC-HbA1c levels alone. Similar HbA1c values using both HPLC and immunoassays (IAs) are noted for these diseases, while discrepancies are noted in the case of hemoglobin variants. Herein, we describe our process of differential diagnosis for hereditary spherocytosis, the most common inherited hemolytic anemia, in a 56-year-old man presenting with a low HPLC-HbA1c level compared to the glucose concentration, concomitant with anemia, jaundice, hyperbilirubinemia, cholelithiasis, and splenomegaly. There was a discrepancy between HbA1c levels measured with HPLC and IAs and glycated albumin levels. The possibility of hemoglobin variants was unlikely, based on the chromatography and isoelectric focusing results. The haptoglobin levels and reticulocyte counts were low and high, respectively. The direct and indirect Coomb's tests were negative. The presence of spherocytes on blood smears and flow cytometric analysis of the eosin-5-maleimide binding test supported a diagnosis of hereditary spherocytosis. We recommend that when a discrepancy between HPLC-HbA1c levels and glucose concentrations is noted, clinicians should consider hemolysis or hemoglobin variants as the diagnosis. It should be considered that a discrepancy between HbA1c levels measured with HPLC and IAs does not specifically exclude hemolysis.

Clinical Diagnosis of Red Cell Membrane Disorders: Comparison of Osmotic Gradient Ektacytometry and Eosin Maleimide (EMA) Fluorescence Test for Red Cell Band 3 (AE1, SLC4A1) Content for Clinical Diagnosis

The measurement of band 3 (AE1, SLC4A1, CD233) content of red cells by eosin-5- maleimide (EMA) staining is swiftly replacing conventional osmotic fragility (OF) test as a tool for laboratory confirmation of hereditary spherocytosis across the globe. Our group has systematically evaluated the EMA test as a method to screen for a variety of anemias in the last 10 years, and compared these results to those obtained with the osmotic gradient ektacytometry (osmoscans) which we have used over three decades. Our overall experience allowed us to characterize the distinctive patterns with the two tests in several congenital erythrocyte membrane disorders, such as hereditary spherocytosis (HS), hereditary elliptocytosis (HE), Southeast Asian Ovalocytosis (SAO), hereditary pyropoikilocytosis (HPP) variants, erythrocyte volume disorders, various red cell enzymopathies, and hemoglobinopathies. A crucial difference between the two methodologies is that osmoscans measure red blood cell deformability of the entire sample of RBCs, while the EMA test examines the band 3 content of individual RBCs. EMA content is influenced by cell size as smaller red cells have lower amount of total membrane than larger cells. The SAO mutation alters the EMA binding site resulting in a lower EMA MCF even as the band 3 content itself is unchanged. Thus, EMA scan results should be interpreted with caution and both the histograms and dot plots should be analyzed in the context of the clinical picture and morphology.

Genotype-phenotype correlation in children with hereditary spherocytosis

Hereditary spherocytosis (HS) is a common inherited haemolytic anaemia attributed to disturbances in five different red cell membrane proteins. We performed a retrospective study of 166 children with HS and describe the clinical phenotype according to the genotype. In 160/166 (97%) children with HS a disease-causing mutation was identified. Pathogenic variants in ANK1, SPTB, SLC4A1 and SPTA1 were found in 49%, 33%, 13% and 5% of patients. Children with SLC4A1-HS had the mildest phenotype, showing the highest haemoglobin (P < 0·001), lowest reticulocyte counts (P < 0·001) and lowest unconjugated bilirubin levels (P = 0·006), and none required splenectomy in childhood (P < 0·001). Conversely, children with autosomal recessive SPTA1-HS had the most severe clinical phenotype, with almost all patients undergoing splenectomy in early childhood. Patients with ANK1 and SPTB variants showed a similar clinical phenotype. Within each gene, variant type or location did not predict disease severity or likelihood of splenectomy. Among patients with a genetic diagnosis, 47 (29%) underwent splenectomy (23 partial; 24 total) while 57 (36%) underwent cholecystectomy. Total splenectomy led to greater improvements in haemoglobin (P = 0·02). Select use of genetic testing (especially in patients without a family history) may help predict clinical phenotype in childhood and guide family counselling.

Evaluation of the Coagulation Profile With Rotational Thromboelastometry in Children With Hereditary Spherocytosis

Hereditary spherocytosis (HS) is a familial hemolytic disorder associated with a variety of mutations that lead to defects in red blood cell (RBC) membrane proteins. There is increasing evidence that hypercoagulability occurs in chronic hemolytic anemia. In this study, changes in the coagulation profile in children with HS were investigated using rotational thromboelastometry. A total of 21 children with HS and 28 healthy children were enrolled in the study between October 2010 and October 2018. Complete blood count, prothrombin time, activated partial thromboplastin time, and fibrinogen level were ascertained, while rotational thromboelastometry assays were used to measure and analyze coagulation time, clot formation time, and maximum clot firmness. There was no difference between the 2 groups in terms of age and sex. The values of hemoglobin and RBC in the patient group were statistically significantly lower than those in the control group (P<0.01, <0.0001, respectively), and the values of platelet count, mean corpuscular hemoglobin concentration, and RBC distribution width were statistically significantly higher than those in the control group (P<0.05, 0.001, <0.0001, respectively). There was no statistically significant difference between the 2 groups in terms of prothrombin time, activated partial thromboplastin time, fibrinogen levels, coagulation time, clot formation time, and maximum clot firmness values. In contrast to other chronic hemolytic anemias, no predisposition to hypercoagulability has been shown in the coagulation profile of children with HS without splenectomy.

Single-cell O2 exchange imaging shows that cytoplasmic diffusion is a dominant barrier to efficient gas transport in red blood cells

Blood is routinely tested for gas-carrying capacity (total hemoglobin), but this cannot determine the speed at which red blood cells (RBCs) exchange gases. Such information is critical for evaluating the physiological fitness of RBCs, which have very limited capillary transit times (<1 s) for turning over substantial volumes of gas. We developed a method to quantify gas exchange in individual RBCs and used it to show that restricted diffusion, imposed by hemoglobin crowding, is a major barrier to gas flows. Consequently, hematological disorders manifesting a change in cell shape or hemoglobin concentration have uncharted implications on gas exchange, which we illustrate using inherited anemias. With its single-cell resolution, the method can identify physiologically inferior subpopulations, providing a clinically useful appraisal of blood quality.

Disorders of oxygen transport are commonly attributed to inadequate carrying capacity (anemia) but may also relate to inefficient gas exchange by red blood cells (RBCs), a process that is poorly characterized yet assumed to be rapid. Without direct measurements of gas exchange at the single-cell level, the barriers to O₂ transport and their relationship with hematological disorders remain ill defined. We developed a method to track the flow of O₂ in individual RBCs by combining ultrarapid solution switching (to manipulate gas tension) with single-cell O₂ saturation fluorescence microscopy. O₂ unloading from RBCs was considerably slower than previously estimated in acellular hemoglobin solutions, indicating the presence of diffusional barriers in intact cells. Rate-limiting diffusion across cytoplasm was demonstrated by osmotically induced changes to hemoglobin concentration (i.e., diffusive tortuosity) and cell size (i.e., diffusion pathlength) and by comparing wild-type cells with hemoglobin H (HbH) thalassemia (shorter pathlength and reduced tortuosity) and hereditary spherocytosis (HS; expanded pathlength). Analysis of the distribution of O₂ unloading rates in HS RBCs identified a subpopulation of spherocytes with greatly impaired gas exchange. Tortuosity imposed by hemoglobin was verified by demonstrating restricted diffusivity of CO₂, an acidic gas, from the dissipative spread of photolytically uncaged H⁺ ions across cytoplasm. Our findings indicate that cytoplasmic diffusion, determined by pathlength and tortuosity, is a major barrier to efficient gas handling by RBCs. Consequently, changes in RBC shape and hemoglobin concentration, which are common manifestations of hematological disorders, can have hitherto unrecognized and clinically significant implications on gas exchange.

A clinical and experimental study of adult hereditary spherocytosis in the Chinese population

Hereditary spherocytosis (HS) is often misdiagnosed due to lack of specific diagnostic methods. Our study summarized clinical characteristics and described the diagnostic workflow for mild and moderate HS in Chinese individuals, using data from 20 adults, 8 of whom presented a familial history for HS. We used scanning electron microscopy (SEM) to diagnose HS. We observed reduced eosin maleimide fluorescence activity (5.50 mean channel fluorescence (MCF) units) in the 10 cases of HS, which differed significantly when compared with 10 normal adults (15.50 units), iron deficiency anemia (15.50 MCF units), and megaloblastic anemia (12.00 MCF units) values (P < .05). Next generation sequencing results revealed that 9 out of 10 patients were found to have mutations in the spectrin alpha chain (SPTB), anchor protein (ANK1), and SLC4A1 genes. These mutations were not reported in the Human Gene Mutation Database (HGMD), 1000 human genome, ExAC, and dbSNP147 databases. Splenectomy proved to be beneficial in alleviating HS symptoms in 10 cases. It was found that for the diagnosis of HS, SEM and next generation gene sequencing method proved to be more ideal than red blood cell membrane protein analysis using sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blotting.

Density, heterogeneity and deformability of red cells as markers of clinical severity in hereditary spherocytosis

Hereditary spherocytosis (HS) originates from defective anchoring of the cytoskeletal network to the transmembrane protein complexes of the red blood cell (RBC). Red cells in HS are characterized by membrane instability and reduced deformability and there is marked heterogeneity in disease severity among patients. To unravel this variability in disease severity, we analyzed blood samples from 21 HS patients with defects in ankyrin, band 3, α-spectrin or β-spectrin using red cell indices, eosin-5-maleimide binding, microscopy, the osmotic fragility test, Percoll density gradients, vesiculation and ektacytometry to assess cell membrane stability, cellular density and deformability. Reticulocyte counts, CD71 abundance, band 4.1 a:b ratio, and glycated hemoglobin were used as markers of RBC turnover. We observed that patients with moderate/severe spherocytosis have short-living erythrocytes of low density and abnormally high intercellular heterogeneity. These cells show a prominent decrease in membrane stability and deformability and, as a consequence, are quickly removed from the circulation by the spleen. In contrast, in mild spherocytosis less pronounced reduction in deformability results in prolonged RBC lifespan and, hence, cells are subject to progressive loss of membrane. RBC from patients with mild spherocytosis thus become denser before they are taken up by the spleen. Based on our findings, we conclude that RBC membrane loss, cellular heterogeneity and density are strong markers of clinical severity in spherocytosis.

Laboratory Approach to Hemolytic Anemia

Hemolytic anemias are a group of disorders with varied clinical and molecular heterogeneity. They are characterized by decreased levels of circulating erythrocytes in blood. The pathognomic finding is a reduced red cell life span with severe anemia or, compensated hemolysis accompanied by reticulocytosis. The diagnostic workup or laboratory approach for hemolytic anemias is based on methodical step-wise testing which includes red blood cell morphology, hematological indices with increased reticulocyte count along with clinical features of hemolytic anemias. If conventional laboratory tests are unable to detect the underlying cause of hemolysis, genetic testing is recommended. Sanger sequencing along with conventional testing is the most efficient way to diagnose the underlying genetic causes, especially in thalassemias/hemoglobinopathies, if required. However, hemolytic anemias being highly heterogeneous disorders, next-generation sequencing-based screening is rapidly becoming an efficient way to decipher the etiologies where common causes have been excluded.

Hereditary spherocytosis with successful splenectomy in a pregnant black South African lady: a case report

Hereditary spherocytosis is a rare cause of chronic haemolytic anaemia. It is rarer in the black population with extremely few cases reported. Initial assessment of a patient with suspected disease should include documenting clinical features of chronic haemolysis and a family history. Its management in pregnancy is challenging and needs a multidisciplinary team. We report on a black South African woman with hereditary spherocytosis and massive splenomegaly presenting with severe haemolytic anaemia at 23^rd week of pregnancy. She had a successful splenectomy.

A tetranucleotide deletion in the ANK1 gene causes hereditary spherocytosis; a case of misdiagnosis

Hereditary spherocytosis is a congenital red blood cell disorder. Typical clinical manifestations include anemia, jaundice and splenomegaly, which overlap with the thalassemia phenotype. Therefore, in high prevalence thalassemia regions, hereditary spherocytosis cases are often misdiagnosed. Here, a case once diagnosed as thalassemia, based on preliminary clinical examinations, underwent genetic testing in our laboratory, where analysis of globin gene mutations proved negative. We conducted both clinical and genetic analyses on the patient and his family. We collected clinical data, performed erythrocyte membrane protein analysis by SDS-PAGE and sequenced the ANK1 gene. We also investigated pathogenic mechanisms through cDNA sequencing and literature studies. From patient clinical data, we diagnosed the patient with moderate to severe hereditary spherocytosis, rather than thalassemia. SDS-PAGE data showed that Ankyrin protein expression was reduced. Sequencing of genomic DNA identified a frameshift mutation (ANK1:c.2394_2397del CAGT). cDNA sequencing showed that the expression of a mutant allele was significantly decreased. Our study corrected a clinical misdiagnosis and confirmed the diagnosis of hereditary spherocytosis in this patient. Identification of such causative mutations is important for accurate downstream patient therapy and is critically important for the prevention/detection of another affected birth. Additionally, the disruption of mRNA transcribed from the mutant allele resulted in a significant reduction in Ankyrin expression and was speculatively considered the pathogenic mechanism behind this mutation.

Deciphering molecular heterogeneity of Indian families with hereditary spherocytosis using targeted next-generation sequencing: First South Asian study

Defects in various erythrocyte membrane proteins genes (ankyrin, band-3, β- and α-spectrin and protein 4·2) can cause hereditary spherocytosis (HS). This molecular heterogeneity of HS, together with co-inherited genetic modifiers, results in marked phenotypic variability among patients. We studied the molecular spectrum and genotype-phenotype correlations in 73 families (with 113 patients) with HS. Deleterious variants including nonsense (42%), deletions (18%), splice site (20%), missense (10%) and duplication/insertion (10%) were found in 47 patients. The variants detected included sporadic and dominantly-inherited defects in ANK1 (53·2%), SPTB (36·2%) and SLC4A1 (4·2%). Compound heterozygous variants in SPTA1 (6·4%) showed autosomal recessive inheritance. Alpha-spectrin variants were associated with severe anaemia and splenectomy alleviated symptoms. Co-inherited glucose-6-phosphate dehydrogenase (G6PD) deficiency was found in 15%. G6PD variants (n = 5) led to greater transfusion requirements (1-8 times) in males with HS. Homozygosity (41%) for the promoter variant of UGT1A1 (Gilbert syndrome) led to a significantly higher mean bilirubin level (126·54 µmol/l) with a higher frequency of cholelithiasis (30%) (P < 0·001). This first-ever south Asian study on the molecular spectrum of HS found ANK1 and SPTB genes variants to be the commonest with inheritance being sporadic/dominant. Next-generation sequencing provided a relatively sensitive and rapid tool for molecular diagnosis with a diagnostic yield of 64·4%.

Clinical utility of targeted gene enrichment and sequencing technique in the diagnosis of adult hereditary spherocytosis

Background

The present study aimed to use the targeted capture and sequencing technique to diagnose adult hereditary spherocytosis (HS). These results were compared with clinical features and laboratory examinations to explore the diagnosis of HS.

Methods

Whole blood and clinical data from ten patients with HS were collected. Genomic DNA was extracted, and a library was prepared. Exomes of patients with ten HS-related genes encoding red cell membrane skeleton protein were captured and sequenced. Bioinformatics analyses were carried out throughout the 1000 Genomes Project, ExAC, dbSNP147, and 1000 Normal Han Population databases.

Results

Gene mutations were found in 9 out of 10 cases of HS. Our data validation showed 90% specificity. Three types of gene mutations were found, including 6 cases of SPTB, 3 cases of ANK1, and 2 cases of SLC4A1. There were 4 mutation forms, including nonsense mutation, missense mutation, shear mutation, and code shift mutation, all of which were new, heterozygous mutations. These variations were predicted to be pathogenic in four databases.

Conclusions

Our data demonstrate that targeted gene enrichment and sequencing methods were an efficient tool for determining genetic etiologies of red blood cell (RBC) membrane disorders and can facilitate accurate diagnosis and genetic counseling. They are also in good agreement with the clinical results.

Clinical and laboratory outcomes following total or partial splenectomy in patients with hereditary spherocytosis

This study compared outcomes following total (TS) or partial splenectomy (PS) among patients with hereditary spherocytosis. Seventy-nine patients (TS = 33, PS = 46) were identified. The follow-up period was longer after PS (59.6 vs. 24.9 months, p < .001). Long-term adverse events occurred more frequently following PS (50% vs. 29%, p = .001). Anemia, jaundice, and fatigue recurred in six patients with PS, leading to five completion splenectomies. Hemoglobin was not different between PS and TS by 5 years post-procedure (12.3 vs. 13.4 g/dL, p = .25). Both PS and TS ameliorate symptoms and improve hematologic parameters. The rate of secondary surgery following PS should be considered when planning the initial surgical procedure.

Indications for Surgery in Non-Traumatic Spleen Disease

The spleen is the largest lymphatic organ that acts as a site for filtration of foreign particles from the blood, erythropoiesis and hematopoiesis. Splenectomy represents the first line of treatment for spontaneous splenic rupture, abscesses, cysts, tumours. It is also used to control hereditary, autoimmune, and myeloproliferative disorders alternatively. Numerous diseases have been indicated for surgery in non-traumatic spleen diseases such as non-traumatic spleen rupture, immune thrombocytopenic purpura (ITP), haemolytic anaemias, Felty’s syndrome, Hodgkin’s and non-Hodgkin’s lymphoma among others. This result because the spleen is the most affected lymphoid organ following its overactivity that occurs during sequestration of dead or disrupted RBCs and lymphocytes. Abdominal pain is one of the major manifestations of splenomegaly, and can also designate other associated complications such as liver cirrhosis or bacterial endocarditis. As a secondary lymphoid organ, the spleen is more often an organ for lymphomas. Although splenectomy is a curative alternative in a few diseases, it is a complementary means of treating several other diseases. Splenectomy is a salvage therapy used when other therapeutic alternatives fail. Despite its indication in numerous diseases, controversies are still inbound of its use.

A previously unrecognized Ankyrin-1 mutation associated with Hereditary Spherocytosis in an Italian family

Hereditary spherocytosis is the most common inherited hemolytic anemia characterized by the presence of spherical-shaped erythrocytes on peripheral blood smear. The clinical manifestations of HS are highly variable, from severe forms to asymptomatic forms. HS is caused by defects in red blood cell membrane proteins, encoded by the ANK1, EPB42, SLC4A1, SPTA1 and SPTB genes. Mutation of the ANK 1 gene is the most common and inheritance is autosomal dominant in 75% of cases. In our case, heterozygous an ANK1 c.4123C > T mutation was identified in a 4-year-old girl, using targeted next-generation sequencing and Sanger sequencing.

Targeted next-generation sequencing identified a novel ANK1 mutation associated with hereditary spherocytosis in a Chinese family

Objectives: Hereditary spherocytosis (HS) represents a group of congenital diseases characterized by sphere-shaped erythrocytes on peripheral blood smears. The typical clinical manifestations of HS include haemolysis, jaundice, splenomegaly, and gallstones. Ankyrin1, encoded by the ANK1 gene, is the predominant protein in red blood cells. Defects in ankyrin1 lead to a decrease in erythrocyte surface area, a spherical shape of erythrocytes and, in particular, loss of membrane elasticity and mechanical stability. The purpose of this study was to investigate a Chinese family with HS to determine the causative gene mutation and explore the genotype-phenotype correlation. Methods: A 4-year-old boy was diagnosed with HS based on typical clinical features. In addition, his father had a high possibility of HS. Targeted next-generation sequencing (NGS) followed by Sanger sequencing was performed in the proband and his parents. Results: One mutation in the ANK1 gene was recognized. c1801-1G > C in exon 17, which leads to splicing defects, was detected. To confirm the c1801-1G > C variant, samples from the proband and his parents were analysed by Sanger sequencing, and Sanger verification showed that this mutation was inherited from the father. Conclusion: The present study confirmed that a novel mutation in ANK1 may be causative of HS, which plays an important role in expanding the mutational spectrum of ANK1 mutations. This may contribute to accurate genetic counselling. And it is helpful for understanding the correlation of the genotype and phenotype.