The diagnostic protocol for hereditary spherocytosis-2021 update

Coexistence of hereditary spherocytosis with SPTB P.Trp1150 gene variant and Gilbert syndrome: A case report and literature review

A congenital protein anomaly in the erythrocyte membrane skeleton causes a hereditary haemolytic illness known as hereditary spherocytosis (HS). The primary characteristic of HS is an increase in the number of tiny spherical red blood cells in the peripheral blood. The chief clinical features of HS include anaemia, jaundice, splenomegaly, spherical erythrocytosis in the blood, chronic anaemia with haemolysis, and recurrent acute attacks. Most patients have a family history; some have autosomal recessive inheritance, whereas most have autosomal dominant inheritance. In cases of severe hyperbilirubinemia disproportionate to haemolysis, other causes of hyperbilirubinemia should be considered. Gilbert syndrome (GS) is an autosomal dominant illness caused by the reduced activity of uridine diphosphate-glucuronosyl transferase lAl and is characterised by intermittent hyperbilirubinemia without any other signs or symptoms of liver disease. The possibility of the coexistence of HS and GS is very limited. Here we present the case of an elderly man with yellow skin and sclera recurring anaemia, and a final diagnosis of coexisting HS and GS.

Could the 14q23.2 microdeletion or AKAP5 haploinsufficiency be a potential cause of intellectual disability?

Intellectual disability is characterized by impairment in at least two of the following areas: social skills, communication skills, self-care tasks, and academic skills. These impairments are evaluated in relation to the expected standards based on the individual's age and cultural levels. Additionally, intellectual disability is typically defined by a measurable level of intellectual functioning, represented by an intelligence quotients core of 70 or below. Autism spectrum disorder is a developmental disability resulting from differences in the brain, often characterized by problems in social communication and interaction, and limited or repetitive behaviors or interests. Hereditary spherocytosis is a disease characterized by anemia, jaundice, and splenomegaly as a result of increased tendency to hemolysis with morphological transformation of erythrocytes from biconcave disc-shaped cells with central pallor to spherocytes lacking central pallor due to hereditary injury of cellular membrane proteins. An 11-year-old female patient was referred to Pediatric Genetics Subdivision due to the presence of growth retardation and a diagnosis of hereditary spherocytosis. Since she also had dysmorphic facial features, such as frontal bossing, broad and prominent forehead, tubular nasal structure, and thin vermillion, genetic tests were performed. Chromosomal microarray analysis revealed a 2.5 Mb deletion in the 14q23.2q23.3 region. Deletion was also identified in the same region in her father, who had the same phenotypic characteristics, including hereditary spherocytosis and learning difficulties. We propose that the PLEKHG3 and AKAP5 genes, which are located in this region, may contribute to the development of intellectual disability.

Precise diagnosis of a hereditary spherocytosis patient with complicated hematological phenotype

Hereditary spherocytosis (HS) is one of the most common causes of hereditary hemolytic anemia. The current diagnostic guidelines for HS are mainly based on a combination of physical examination and laboratory investigation. However, some patients present with complicated clinical manifestations that cannot be explained by routine diagnostic protocols. Here, we report a rare HS case of mild anemia with extremely high indirect bilirubin levels and high expression of fetal hemoglobin. Using whole exome sequencing analysis, this patient was identified as a heterozygous carrier of a de novo SPTB nonsense mutation (c.605G > A; p.W202*) and a compound heterozygous carrier of known UGT1A1 and KLF1 mutations. This genetic analysis based on the interpretation of the patient's genomic data not only achieved precise diagnosis by an excellent explanation of the complicated phenotype but also provided valuable suggestions for subsequent appropriate approaches for treatment, surveillance and prophylaxis.

Catalase, Glutathione Peroxidase, and Peroxiredoxin 2 in Erythrocyte Cytosol and Membrane in Hereditary Spherocytosis, Sickle Cell Disease, and β-Thalassemia

Catalase (CAT), glutathione peroxidase (GPx), and peroxiredoxin 2 (Prx2) can counteract the deleterious effects of oxidative stress (OS). Their binding to the red blood cell (RBC) membrane has been reported in non-immune hemolytic anemias (NIHAs). Our aim was to evaluate the relationships between CAT, GPx, and Prx2, focusing on their role at the RBC membrane, in hereditary spherocytosis (HS), sickle cell disease (SCD), β-thalassemia (β-thal), and healthy individuals. The studies were performed in plasma and in the RBC cytosol and membrane, evaluating OS biomarkers and the enzymatic activities and/or the amounts of CAT, GPx, and Prx2. The binding of the enzymes to the membrane appears to be the primary protective mechanism against oxidative membrane injuries in healthy RBCs. In HS (unsplenectomized) and β-thal, translocation from the cytosol to the membrane of CAT and Prx2, respectively, was observed, probably to counteract lipid peroxidation. RBCs from splenectomized HS patients showed the highest membrane-bound hemoglobin, CAT, and GPx amounts in the membrane. SCD patients presented the lowest amount of enzyme linkage, possibly due to structural changes induced by sickle hemoglobin. The OS-induced changes and antioxidant response were different between the studied NIHAs and may contribute to the different clinical patterns in these patients.

Current Status of Molecular Diagnosis of Hereditary Hemolytic Anemia in Korea

Hereditary hemolytic anemia (HHA) is considered a group of rare hematological diseases in Korea, primarily because of its unique ethnic characteristics and diagnostic challenges. Recently, the prevalence of HHA has increased in Korea, reflecting the increasing number of international marriages and increased awareness of the disease. In particular, the diagnosis of red blood cell (RBC) enzymopathy experienced a resurgence, given the advances in diagnostic techniques. In 2007, the RBC Disorder Working Party of the Korean Society of Hematology developed the Korean Standard Operating Procedure for the Diagnosis of Hereditary Hemolytic Anemia, which has been continuously updated since then. The latest Korean clinical practice guidelines for diagnosing HHA recommends performing next-generation sequencing as a preliminary step before analyzing RBC membrane proteins and enzymes. Recent breakthroughs in molecular genetic testing methods, particularly next-generation sequencing, are proving critical in identifying and providing insight into cases of HHA with previously unknown diagnoses. These innovative molecular genetic testing methods have now become important tools for the management and care planning of patients with HHA. This review aims to provide a comprehensive overview of recent advances in molecular genetic testing for the diagnosis of HHA, with particular emphasis on the Korean context.

Novel mutation in alpha-spectrin gene in Saudi patients with hereditary spherocytosis

Hereditary spherocytosis (HS) is the most common hereditary hemolytic disorder induced by red blood cell (RBC) membrane defect. This study was undertaken to determine mutations in genes associated with RBC membrane defect in patients with HS such as α-spectrin gene (SPTA1), β-spectrin gene (SPTB), ankyrin gene (ANK1), band 3 anion transport gene (SLC4A1) and erythrocyte membrane protein band 4.1 gene (EPB41). Blood samples were collected from 23 unrelated patients with HS. Patients were diagnosed according to the guidelines from the British Society for Hematology. All hematological examinations for the determination of RBC abnormalities and osmotic fragility tests were conducted. Genomic DNA were extracted from peripheral blood cells and coding exons of known genes for hereditary spherocytosis were enriched using Roche/KAPA sequence capture technology and sequenced on an Illumina system via next-generation sequencing (NGS). The data showed that most of the HS patients confirmed splenomegaly and showed elevated reticulocytes and abnormal bilirubin values. NGS analysis identified the heterozygous variant c.5501G > A in the exon 39 of SPTA1 gene, resulted in a Trp1834*, which leads to a premature stop codon and subsequent mRNA degradation (nonsense- mediated decay) or truncation in α spectrin. Moreover, our data also revealed conventional mutations in genes SPTB, ANK, SLC4A1 and EBP41 in severe patients of HS. In short, this is the first report that determined a novel mutation c.5501G > A in SPTA1 gene in the Saudi population. To the best of our knowledge, this variant c.5501G > A has not been described in global literature so far. This novel mutation in SPTA1 gene is unique in the Saudi population.

Molecular characteristics of hereditary red blood cell membrane disorders in Thailand: a multi-center registry

Red blood cell (RBC) membrane disorders represent a significant category of hereditary hemolytic anemia; however, information from Southeast Asia is limited. We established a national registry aiming to characterize RBC membrane disorders and their molecular features in Thailand. A total of 100 patients (99 kindreds) diagnosed with RBC membrane disorders between 2011 and 2020 from seven university hospitals were enrolled. The most prevalent disorders observed were hereditary elliptocytosis (HE; n=33), hereditary pyropoikilocytosis (HPP; n=28), hereditary spherocytosis (HS; n=19), Southeast Asian ovalocytosis (SAO; n=10 of 9 kindreds), and two cases of homozygous SAO. The remaining cases were grouped as unclassified membrane disorder. Seventy-six patients (76%) were molecularly confirmed by PCR, direct DNA sequencing, or hi-throughput sequencing. The primary causative gene for HE and HPP was SPTB, accounting for 28 out of 29 studied alleles for HE and 56 of 56 studied alleles for HPP. In the case of HS, dominant sporadic mutations in the ANK1 gene (n=4) and SPTB gene (n=3) were identified as the underlying cause. Notably, the four most common variants causing HE and HPP were SPTB Providence (c.6055 T>C), SPTB Buffalo (c.6074 T>G), SPTB Chiang Mai (c.6224 A>G), and SPTB c.6171__82delins TGCCCAGCT. These recurrent SPTB mutations accounted for 79 out of 84 mutated SPTB alleles (94%). In summary, HE and hereditary HPP associated with recurrent SPTB mutations are the predominant types of RBC membrane disorders observed in Thailand. These findings have significant implications for the clinical management and future research of RBC membrane disorders in the region.

A Case Report of Hemolytic Hyponatremia

Hereditary spherocytosis/elliptocytosis is a non-immune hemolytic anemia caused by an alteration in the erythrocyte membrane that predisposes the cell to its lysis. This report presents a case of a 42-year-old woman with a history of spontaneous abortion, associated with postpartum bleeding, chronic anemia, and premature menopause. After five years, she consulted due to alterations in the state of consciousness and severe symptomatic hyponatremia, with a diagnosis of hypopituitarism, explained by a late Sheehan syndrome. During hospitalization, she developed non-immune hemolytic anemia associated with a positive osmotic fragility test. A diagnosis of hereditary spherocytosis/elliptocytosis was made. We correlate blood hypoosmolarity as a trigger with the in vitro hypotonic solution of the osmotic fragility test for the diagnosis of this disease. This association is not reported in the literature; in our case, we show the concomitant improvement of anemia with the increase in sodium levels and hormonal replacement.

Coinheritance of hereditary spherocytosis with haemochromatosis: next-generation sequencing reveals

We report the case of a man in his 50s with extravascular haemolysis, fluctuating indirect hyperbilirubinaemia, elevated transferrin saturation with hyperferritinaemia and normal liver enzymes. Spherocytes were detected in a blood smear and a mutation of unknown significance, c.1626+1G>A p.?, in intron 13 of the SLC4A1 gene, was identified by next-generation sequencing (NGS). The same mutation was found in his daughter, who presented with similar laboratory changes, confirming the diagnosis of hereditary spherocytosis. Abdominal MRI showed hepatosplenomegaly with hepatic iron overload. In this context of haemolysis (without anaemia) and iron overload, a diagnosis of haemochromatosis was presumed. NGS confirmed the presence of the variants p.(His63Asp) and p.(Cys282Tyr) in heterozygosity in the HFE gene. We report this case for the rarity of co-existing two haematological diseases counteracting each other.

The Correlation Between Clinical Phenotype and Genotype of Hereditary Spherocytosis

Objective: Hereditary spherocytosis (HS) is a common hereditary hemolytic disease. This study aimed to explore the correlation between the phenotype and mutant genotype of HS to improve the clinical understanding of HS. Methods: This study reported a case of spontaneous mutation of the ANK1 gene in HS, reviewed previous studies on the genotype-phenotype correlation of HS, statistically analyzed the main types of gene mutations in HS, and summarized the clinical data of patients. Results: This patient had clinical manifestations of anemia, splenomegaly, peripheral blood smear with increased spherocytosis, and bilirubin, confirmed as ANK1 gene mutant HS by gene detection. In addition, this study included 14 previous studies on genotype-phenotype correlation, collected data, and determined that the ANK1 and SPTB genes were the most common types of gene mutations in HS patients. The mutant HS of the ANK1 gene would lead to lower hemoglobin levels. Conclusion: The results of this study showed that ANK1 and SPTB were the most common types of gene mutations in HS patients. Compared with patients with the SPTB genotype HS, patients with ANK1 mutant HS had more severe extravascular hemolysis, and a higher proportion needed splenectomy in early childhood.

Case report: Genetic analysis of a novel intronic inversion variant in the SPTB gene associated with hereditary spherocytosis

Background: Hereditary spherocytosis (HS) is a congenital haemolytic anaemia attributed to dysregulation or abnormal quantities of erythrocyte membrane proteins. Currently, the most common erythrocytic gene, spectrin β (SPTB), variants are located in exons and give rise to mRNA defects. However, the genetic characteristics and pathogenic mechanisms of SPTB intronic variants are not completely understood. This study aimed to analyse a rare intronic inversion variant in the SPTB gene associated with HS, and explore the impact of the variant on SPTB mRNA splicing. Method: The clinical manifestations of the patient were summarised and analysed for spherocytosis phenotype diagnosis. The pathogenic variant was identified in the proband using targeted next-generation and Sanger sequencing. RNA sequencing was performed to analyse whether SPTB gene splicing and expression were affected. Results: Targeted next-generation sequencing identified a novel disease-associated intronic inversion variant of the SPTB gene in the proband. The inversion variant was located between intron 19 and 20, and contained the entire exon 20 and partial sequences of adjacent introns. Sanger sequencing confirmed that the intronic inversion variant only appeared in the genome of the proband, not in his parents. RNA sequencing revealed that the variant could result in the skipping of exon 20 and reduced expression of SPTB mRNA. Conclusion: This study identifies a rare intronic inversion variant in the SPTB gene associated with hereditary spherocytosis. The pathogenic variant can lead to exon 20 skipping and decreased SPTB gene expression. This finding has not been previously reported in any literature. This study can expand the intronic variant spectrum of the SPTB gene, deepen our understanding of HS pathogenesis, and contribute to the genetic diagnosis and clinical management of patients.

Clinical value of combined predictors of RET%, γ-GT, LDH in the ABO neonatal hemolytic disease

Objective

The purpose of this study is to examine the prognostic significance of the amalgamated indicators, reticulocyte percentage (RET%), lactate dehydrogenase (LDH), and γ-Glutamyltransferase (γ-GT), in neonatal ABO hemolytic disease.

Methods

A total of 137 hospitalized children with pathological jaundice were included. Based on their medical conditions, they were categorized into two groups, hemolytic (67 cases) and non-hemolytic (70 cases). Pearson linear correlation and binary logistic multivariate analysis were used to analyze LDH, γ-GT, RET% and hemolysis. Furthermore, the predictive value of the combined predictors of RET%, LDH, and γ-GT on ABO neonatal hemolytic disease was evaluated using the ROC curve analysis.

Results

The laboratory indexes of the two groups were subject to analysis using binary logistic regression to identify suspicious influencing factors. The study revealed that RET%, LDH, and γ-GT were independent risk factors for hemolysis. Pearson linear correlation analysis indicated a positive correlation between LDH and γ-GT with RET% (r = 0.529, P < 0.01; r = 0.526, P = <0.01, respectively). Furthermore, the predictive value of each combined predictor was obtained using the ROC curve, and it was observed that combined predictor L (RET% + LDH + γ-GT)>L1 (RET% + LDH)>L2 (RET% + γ-GT).

Conclusion

Combined predictor L (RET% + LDH + γ-GT)demonstrate its optimal diagnostic efficacy, offering a novel approach towards diagnosing early-onset ABO hemolytic disease of the newborn.

Integrative preimplantation genetic testing analysis for a Chinese family with hereditary spherocytosis caused by a novel splicing variant of SPTB

Hereditary spherocytosis (HS), the most common inherited hemolytic anemia disorder, is characterized by osmotically fragile microspherocytic red cells with a reduced surface area on the peripheral blood smear. Pathogenic variants in five erythrocyte membrane structure-related genes ANK1 (Spherocytosis, type 1; MIM#182900), SPTB (Spherocytosis, type 2; MIM#616649), SPTA1 (Spherocytosis, type 3; MIM#270970), SLC4A1 (Spherocytosis, type 4; MIM#612653) and EPB42 (Spherocytosis, type 5; MIM#612690) have been confirmed to be related to HS. There have been many studies on the pathogenic variants and mechanisms of HS, however, studies on how to manage the transmission of HS to the next-generation have not been reported. In this study, we recruited a patient with HS. Targeted next-generation sequencing with a panel of 208 genes related to blood system diseases detected a novel heterozygous variant in the SPTB: c.300+2dup in the proband. Sanger sequencing of variant alleles and haplotype linkage analysis of single nucleotide polymorphism (SNP) based on next-generation sequencing were performed simultaneously. Five embryos were identified with one heterozygous and four not carrying the SPTB variant. Single-cell amplification and whole genome sequencing showed that three embryos had varying degrees of trisomy mosaicism. One of two normal embryos was transferred to the proband. Ultimately, a healthy boy was born, confirmed by noninvasive prenatal testing for monogenic conditions (NIPT-M) to be disease-free. This confirmed our successful application of PGT in preventing transmission of the pathogenic variant allele in the HS family.

Genetic mutation analysis of hereditary spherocytosis in Guangxi Zhuang Autonomous Region

Hereditary spherocytosis (HS) is a common, hereditary hemolytic anemia (HHA) that is attributed to the disturbance of five erythrocyte membrane proteins. HS is also common in Guangxi, China. Target region capture high-throughput sequencing technology was used to analyze genetic mutations found in HS patients. Pedigree analysis was also performed, in some cases, to provide an optimized approach for the etiological diagnosis of complex, hereditary hemolytic anemia. Blood samples from the probands and their families were assessed by laboratory tests, target region capture high-throughput sequencing technology, and Sanger sequencing. We detected 79 HS patients from 37 unrelated families. The mutations observed in these patients were found mainly in four HS-related genes. These included SLC4A1, which was mutated in 31.65% of patients (25/79), SPTA1 (30.78% (24/79)), EPB42 (6.33% (5/79)), and SPTB (5.06% (4/79)). Composite genotype was observed in 26.58% (21/79) of patients and included mutations in two or more HS-related genes or mutations in HS-related genes combined with thalassemia or G6PD deficiency. No significant differences in clinical symptoms were found among patients of various genotypes except total bilirubin. Mean reticulocyte volume (MRV) and mean sphered cell volume (MSCV) of the composite genotype were significantly different from other groups. A total of 28 mutation types were found in HS-related genes. Using high-throughput sequencing technology, we also found some cases that had been misdiagnosed. MRV and MSCV are more significant in compound mutations as sensitive determinants of HS. High-throughput sequencing technology can be used to provide a more effective etiological diagnostic method for HS, with high efficiency and specificity.

Clinical Presentation of Parvovirus B19 Infection in Adults Living with HIV/AIDS: A Case Series

Parvovirus B19 (B19V) infection varies clinically depending on the host's immune status. Due to red blood cell precursors tropism, B19V can cause chronic anemia and transient aplastic crisis in patients with immunosuppression or chronic hemolysis. We report three rare cases of Brazilian adults living with human immunodeficiency virus (HIV) with B19V infection. All cases presented severe anemia and required red blood cell transfusions. The first patient had low CD4⁺ counts and was treated with intravenous immunoglobulin (IVIG). As he remained poorly adherent to antiretroviral therapy (ART), B19V detection persisted. The second patient had sudden pancytopenia despite being on ART with an undetectable HIV viral load. He had historically low CD4⁺ counts, fully responded to IVIG, and had undiagnosed hereditary spherocytosis. The third individual was recently diagnosed with HIV and tuberculosis (TB). One month after ART initiation, he was hospitalized with anemia aggravation and cholestatic hepatitis. An analysis of his serum revealed B19V DNA and anti-B19V IgG, corroborating bone marrow findings and a persistent B19V infection. The symptoms resolved and B19V became undetectable. In all cases, real time PCR was essential for diagnosing B19V. Our findings showed that adherence to ART was crucial to B19V clearance in HIV-patients and highlighted the importance of the early recognition of B19V disease in unexplained cytopenias.

Targeted next-generation sequencing identifies novel deleterious variants in ANK1 gene causing severe hereditary spherocytosis in Indian patients: expanding the molecular and clinical spectrum

Hereditary Spherocytosis (HS) is a common cause of hemolytic anemia varying from mild to severe hemolysis due to defects in red cell membrane protein genes, namely ANK1, SPTB, SPTA1, SLC4A1, and EPB42. These genes are considerably very large spaning 40-50 exons making gene-by-gene analysis costly and laborious by conventional methods. In this study, we explored 26 HS patients harboring 21 ANK1 variants identified by next-generation sequencing (NGS), characteristics and spectrum of the detected ANK1variants were analyzed in this study. Clinically, all the HS patients showed moderate to severe transfusion-dependent hemolytic anemia, some requiring splenectomy. We identified 13 novel and 8 reported variants, mainly 9 frameshifts, 2 missense, 6 nonsense, and 4 splice site ANK1 variants, using NGS technology. Frameshifts were remarkably the most common variant type seen in Indian HS patients with ANK1 gene defects. We have also explored expression levels of red cell membrane ankyrin protein by flow cytometry in 14 HS patients with ANK1 gene defects and a significant reduction in ankyrin protein expression has been found. This report mainly illustrates the molecular and phenotypic heterogeneity of ANK1 variants causing HS in Indian patients. Ankyrin-1 mutations are a significant cause of loss of function in dominant HS in the Indian population. Comprehensive genetic and phenotypic evaluation assists in implementing the knowledge of genetic patterns and spectrum of ANK1 gene variants, providing molecular support for HS diagnosis.

Clinical manifestations of 17 Chinese children with hereditary spherocytosis caused by novel mutations of the ANK1 gene and phenotypic analysis

Background: Hereditary spherocytosis (HS) is an autosomal dominant (AD) and autosomal recessive (AR) disorder that is mostly caused by mutations of the erythrocyte membrane-related gene ANK1. Methods: Clinical and genetic testing data of 17 HS children with ANK1 gene mutations were retrospectively collected. Clinical manifestations and phenotypic analysis of HS were summarized based on our experience and literature review. Results: A total of 17 mutations of the ANK1 gene were identified from 17 probands (12 sporadic cases and five familial cases), including 15 novel mutations and two previously reported ones. Among the 15 novel variants of ANK1, there were four non-sense mutations, four frameshift mutations, three splicing mutations, three missense mutations and one in-frame deletion of three amino acids. In the present study, HS patients with mutations in membrane binding domains had significantly lower hemoglobin (Hb) levels and higher total bilirubin (T-Bil) levels than those with mutations in regulatory domains. After reviewing and analyzing all available published reports of Chinese HS patients carrying ANK1 mutations in PubMed and Chinese journals, there were no significant differences in Hb, Ret and T-Bil between different mutation types or mutation regions. Conclusion: Mutations of the ANK1 can be inherited or de novo. Clinical manifestations of HS in children caused by ANK1 mutations are similar to those of other types of hemolytic anemia. Our report expands the mutation spectrum of HS, thus providing references for clinical management and genetic counseling of HS.

A large family of hereditary spherocytosis and a rare case of hereditary elliptocytosis with a novel SPTA1 mutation underdiagnosed in Taiwan: A case report and literature review

RATIONALE

Hereditary spherocytosis (HS) has a defect in the vertically connected proteins on the cell membrane of red blood cells (RBC). Hereditary elliptocytosis (HE) has a defect in proteins that connect the cell membrane horizontally. We reported two families of RBC membrane disorders in Taiwanese, one was HS and the other was HE.

PATIENT CONCERNS

Case 1. A 19-year-old male student with chronic jaundice and splenomegaly. His mother, maternal uncle, grandmother, and many members of older generations also had splenomegaly and underwent splenectomy. Case 2. A 40-year-old man has experienced pallor and jaundice since the age of 20 and was found to have splenomegaly, and gall bladder stones in the older age. His younger sister also had pallor and jaundice for a long time.

DIAGNOSES

In case 1, a peripheral blood smear showed 20% spherocytes. Eosin-5-maleimide labeled RBC by flow cytometry showed a result of 30.6 MCF (cutoff value: 45.5 MCF). He was diagnosed with HS. The gene analysis identified a heterozygous mutation with c.166A > G (p.Lys56Glu) in the SLC4A1 gene in this proband, his mother, and maternal uncle. In case 2, more than 40% of ellipsoid RBC present in the peripheral blood smear. He was diagnosed with HE. Genetic analysis of the SPTA1 gene identified a novel heterozygous exon2, c.86A > C, p.Gln29Prol mutation.

INTERVENTIONS

The two patients had compensated anemia, clinical follow-up instead of splenectomy was done.

OUTCOMES

The two patients had normal daily activities and lives.

LESSONS

We reported two Taiwanese families, one was hereditary spherocytosis affected by a heterozygous mutation with c.166A > G (p.Lys56Glu) in SLC4A1, and the other was hereditary elliptocytosis caused by a novel heterozygous SPTA1 gene mutation, c. 86A > C, p.Gln29Prol. These 2 seemingly common hereditary red blood cell membrane protein defects induced by hemolysis are usually underdiagnosed or misdiagnosed.

De novo variations of ANK1 gene caused hereditary spherocytosis in two Chinese children by affecting pre-mRNA splicing

BACKGROUND AND AIMS

Hereditary spherocytosis (HS) is one of the most common hereditary haemolytic disorders. Here, two unrelated families with the probands displaying typical manifestations of HS were enrolled. Our study aimed to characterize the effect of two novel variants in HS patients on gene splicing to help minimize the rate of misdiagnosis of HS and enhance clinicians' understanding of the disease.

PARTICIPANTS AND METHODS

A retrospective review was conducted. Peripheral blood samples were collected from all the family members, and genomic DNA was extracted for genetic diagnostics. First, high-throughput sequencing technology was used for the preliminary screening of candidate causative variants. Thereafter, the variants were verified via Sanger sequencing. Furthermore, a pathogenicity analysis of the detected variants was performed including in silico prediction and in vitro experiments. We constructed matched wild-type and mutant-type minigene plasmid of ANK1 based on HEK293T cells to address the effects of variants on mRNA splicing.

RESULTS

The c.1305 + 2 T > A (family1) and c.1305 + 2del (family2) variants were detected in the ANK1 gene. These two de novo mutations described by us which have not been reported prior to this study. Moreover, the validation results of splicing reporter systems revealed that the intronic mutations resulted in abnormal pre-mRNA splicing. Specifically, the minigene plasmid expressing the c.1305 + 2 T > A variant transcribed the two aberrant transcripts: r.1305_1306ins1305 + 1_1305 + 229 and r.1305_1306ins1305 + 1_1305 + 552. The minigene plasmid expressing c.1305 + 2del transcribed the two aberrant transcripts: r.1305_1306ins1305 + 1_1305 + 228 and r.1305_1306ins1305 + 1_1305 + 551.

CONCLUSION

The two de novo variants identified in the ANK1 gene were the genetic etiology of the probands with HS in our study. Our findings further enrich the HS genotype database and provide a basis for genetic counselling and molecular diagnosis.

Congenital Disorders of Red Blood Cells

See Bonus NeoBriefs videos and downloadable teaching slides Understanding the physiologic process of red blood cell development in utero and subsequent erythropoiesis in the neonate is crucial as this determines red blood cell structure and therefore function, which is vital to neonatal health. Infants frequently experience anemia, and special consideration must be given to the evaluation of these infants to determine the correct etiology. Traditionally, anemia is conceptualized in terms of inadequate red blood cell production, increased red blood cell destruction, or whole blood loss. This framework translates well to inherited red blood cell defects, which include genetic abnormalities in bone marrow productivity or structure of the red blood cell membrane, enzymes, or hemoglobin. This article highlights fetal and neonatal erythropoiesis and the underlying etiologies of the inherited red blood cell disorders, as well as reviews the appropriate diagnostic evaluation and next steps in management. It is imperative that neonatal clinicians remain informed about these disorders to enable early recognition and treatment, and ultimately to improve outcomes in affected infants.

Hereditary spherocytosis complicated by intrahepatic cholestasis: two case reports

Background

Hereditary spherocytosis (HS) is not a rare disease in the department of hematology; however, in the late stage of the disease, patients often have very severe cholestasis and are referred to the department of hepatology. Hepatologists may have trouble determining the source of cholestasis, causing treatment difficulties.

Case Description

We report two 20-year-old patients complaining of "skin and eyes turned to yellow". Patient 1 had no previous hematologic disorders, and patient 2 had a history of anemia without treatment. Laboratory tests suggested anemia and elevated bilirubin in both patients. The direct bilirubin levels were more significantly elevated than the indirect bilirubin levels in both patients, and the patients both suffered from abdominal pain and pancreatitis. However, the degree of anemia could not fully explain the jaundice. Magnetic resonance imaging findings suggested the presence of hepatosplenomegaly and gallstones. Genetic testing identified new mutations in the relevant genes, ultimately confirming the diagnosis of HS. The liver biopsy results for both patients showed obvious intrahepatic cholestasis. Patient 1 underwent splenectomy at a bilirubin level of 125.4 µmol/L, and the bilirubin level returned to normal after surgery, with a good prognosis. However, Patient 2 suffered from pancreatitis during hospitalization and was unable to undergo splenectomy. Endoscopic retrograde cholangiopancreatography was implemented, but the bilirubin level continued to rise, and Patient 2 ultimately gave up treatment and passed away.

Conclusions

For hepatologists, identifying the source of jaundice (hemolysis, hepatocyte destruction, or biliary obstruction) is important for treatment, supplemented by liver biopsy and genetic testing if necessary. In the 2 cases covered in this article, early-stage HS caused hemolytic jaundice with predominantly elevated indirect bilirubin, and as the disease progressed, patients developed severe cholestasis probably related to transient biliary obstruction caused by gallstones and hepatocellular injury due to abnormal bilirubin metabolism. In addition, in patients with HS combined by intrahepatic cholestasis, early consideration of splenectomy may delay disease progression and achieve a better prognosis. Of course, this conclusion needs to be confirmed by more clinical studies.

Intraoperative Cell-Saver Caused More Autologous Salvage Hemolysis in a Hereditary Spherocytosis Patient Than in a Normal Erythrocyte Patient

Hereditary spherocytosis is a common red blood cell disease caused by an inherited red blood cell membrane defect, leading to a spherical shape and propensity for hemolysis. There is a lack of reports on intraoperative autologous blood transfusion for hereditary spherocytosis patients. We hereby report our recent experience with using the Cell Saver^® system for intraoperative red blood cell salvage on a hereditary spherocytosis patient. There was a drastic increase in salvaged blood free-hemoglobin compared with the preoperative sample (82.6 mg/dl vs. 6.2 mg/dl) which indicated severe hemolysis. Although our patient recovered smoothly with a normal liver and renal function test and reported no adverse reaction during follow-up, it is noteworthy that severe hemolysis could happen during the cell salvage process for patients with hemolytic anemia, as there are similar reports on sickle cell anemia, beta-thalassemia intermedia, and paroxysmal nocturnal hemoglobinuria. Therefore, more clinical attention and thorough research should be drawn into this perspective, namely, hemolysis during the red blood cell salvage process for patients with hemolytic anemia.

Concomitant Hereditary Spherocytosis and Pyruvate Kinase Deficiency in a Spanish Family with Chronic Hemolytic Anemia: Contribution of Laser Ektacytometry to Clinical Diagnosis

Background: Hereditary spherocytosis (HS) and pyruvate kinase deficiency (PKD) are the most common causes of hereditary chronic hemolytic anemia. Here, we describe clinical and genetic characteristics of a Spanish family with concomitant β-spectrin (SPTB) c.647G>A variant and pyruvate kinase (PKLR) c.1706G>A variant. Methods: A family of 11 members was studied. Hematological investigation, hemolysis tests, and specific red cell studies were performed in all family members, according to conventional procedures. An ektacytometric study was performed using the osmoscan module of the Lorca ektacytometer (MaxSis. RR Mechatronics). The presence of the SPTB and PKLR variants was confirmed by t-NGS. Results: The t-NGS genetic characterization of the 11 family members showed the presence of a heterozygous mutation for the β-spectrin (SPTB; c.647G>A) in seven members with HS, three of them co-inherited the PKLR variant c.1706G>A. In the remaining four members, no gene mutation was found. Ektacytometry allowed a clear diagnostic orientation of HS, independently from the PKLR variant. Conclusions: This family study allows concluding that the SPTB mutation, (c.647G>A) previously described as likely pathogenic (LP), should be classified as pathogenic (P), according to the recommendations for pathogenicity of the American College of Medical Genetics and the Association for Molecular Pathology. In addition, after 6 years of clinical follow-up of the patients with HS, it can be inferred that the chronic hemolytic anemia may be attributable to the SPTB mutation only, without influence of the concomitant PKLR. Moreover, only the family members with the SPTB mutation exhibited an ektacytometric profile characteristic of HS.