Beta-thalassemia

The Genetic Architecture of High Bone Mass

The phenotypic trait of high bone mass (HBM) is an excellent example of the nexus between common and rare disease genetics. HBM may arise from carriage of many 'high bone mineral density [BMD]'-associated alleles, and certainly the genetic architecture of individuals with HBM is enriched with high BMD variants identified through genome-wide association studies of BMD. HBM may also arise as a monogenic skeletal disorder, due to abnormalities in bone formation, bone resorption, and/or bone turnover. Individuals with monogenic disorders of HBM usually, though not invariably, have other skeletal abnormalities (such as mandible enlargement) and thus are best regarded as having a skeletal dysplasia rather than just isolated high BMD. A binary etiological division of HBM into polygenic vs. monogenic, however, would be excessively simplistic: the phenotype of individuals carrying rare variants of large effect can still be modified by their common variant polygenic background, and by the environment. HBM disorders-whether predominantly polygenic or monogenic in origin-are not only interesting clinically and genetically: they provide insights into bone processes that can be exploited therapeutically, with benefits both for individuals with these rare bone disorders and importantly for the many people affected by the commonest bone disease worldwide-i.e., osteoporosis. In this review we detail the genetic architecture of HBM; we provide a conceptual framework for considering HBM in the clinical context; and we discuss monogenic and polygenic causes of HBM with particular emphasis on anabolic causes of HBM.

Transcriptome Analyses of β-Thalassemia -28(A>G) Mutation Using Isogenic Cell Models Generated by CRISPR/Cas9 and Asymmetric Single-Stranded Oligodeoxynucleotides (assODNs)

β-thalassemia, caused by mutations in the human hemoglobin β (HBB) gene, is one of the most common genetic diseases in the world. The HBB -28(A>G) mutation is one of the five most common mutations in Chinese patients with β-thalassemia. However, few studies have been conducted to understand how this mutation affects the expression of pathogenesis-related genes, including globin genes, due to limited homozygote clinical materials. Therefore, we developed an efficient technique using CRISPR/Cas9 combined with asymmetric single-stranded oligodeoxynucleotides (assODNs) to generate a K562 cell model with HBB -28(A>G) named K562-28(A>G). Then, we systematically analyzed the differences between K562-28(A>G) and K562 at the transcriptome level by high-throughput RNA-seq before and after erythroid differentiation. We found that the HBB -28(A>G) mutation not only disturbed the transcription of HBB, but also decreased the expression of HBG, which may further aggravate the thalassemia phenotype and partially explain the more severe clinical outcome of β-thalassemia patients with the HBB -28(A>G) mutation. Moreover, we found that the K562-28(A>G) cell line is more sensitive to hypoxia and shows a defective erythrogenic program compared with K562 before differentiation. Importantly, all abovementioned abnormalities in K562-28(A>G) were reversed after correction of this mutation with CRISPR/Cas9 and assODNs, confirming the specificity of these phenotypes. Overall, this is the first time to analyze the effects of the HBB -28(A>G) mutation at the whole-transcriptome level based on isogenic cell lines, providing a landscape for further investigation of the mechanism of β-thalassemia with the HBB -28(A>G) mutation.

Ocular findings in patients with transfusion-dependent β-thalassemia in southern Iran

Background

Ocular involvement may occur via several mechanisms in patients with transfusion-dependent β-thalassemia (TDT) mainly chronic anemia, iron overload and iron chelator toxicity. We aimed to evaluate the frequency of abnormal ocular findings and their relationship with hematologic parameters in TDT patients.

Methods

In this cross-sectional study from January 2018 to January 2019, a total of 79 patients with TDT over the age of 18 who were on iron-chelation therapy (ICT) were consecutively investigated. All patients were registered at the Thalassemia Comprehensive Center affiliated with Shiraz University of Medical Sciences, Shiraz, Southern Iran. Complete ophthalmic examination was performed by an expert ophthalmologist. Clinical and hematologic parameters were collected from the patients´ medical records.

Results

The mean age ± standard deviation (SD) of the patients was 28.4 ± 5.6 years (range: 18–43). Twenty-four patients (30.4%) were male and 29 (36.7%) were splenectomized. The mean ± SD of the best-corrected visual acuity (VA) was 0.960 ± 0.086 decimal, (range: 0.6–1), 0.016 ± 0.046 logMar, (range: 0–0.2). The frequency of patients with VA > 0.1 logMar was 3 (3.8%). The mean intraocular pressure (IOP) was 14.88 ± 3.34 (6–25) mmHg. Fundus abnormalities were observed in 8 patients (10.1%), consisting of increased cup-disk ratio (3.8%), vessel tortuosity (2.5%), retinal pigment epithelium degeneration (2.5%), myelinated nerve fiber layer (1.3%), and internal limiting membrane wrinkling (1.3%). No significant association was observed between fundus abnormalities, VA, or IOP with hematologic parameters (P > 0.05). TDT patients with diabetes mellitus had significantly higher IOP (P = 0.010) but similar frequency of fundus abnormalities with non-diabetic patients (P > 0.05).

Conclusions

The frequency of ocular abnormalities in our patients was lower than the previous reports. The frequency of fundus abnormalities were similar in diabetic and non-diabetic thalassemia patients indicating close monitoring and proper management of the disease and comorbidities in these patients.

Nucleic Acid Therapy for β-Thalassemia

β-thalassemia is caused by mutations in the β-globin gene which diminishes or abolishes β-globin chain production. This reduction causes an imbalance of the α/β-globin chain ratio and contributes to the pathogenesis of the disease. Several approaches to reduce the imbalance of the α/β ratio using several nucleic acid-based technologies such as RNAi, lentiviral mediated gene therapy, splice switching oligonucleotides (SSOs) and gene editing technology have been investigated extensively. These approaches aim to reduce excess free α-globin, either by reducing the α-globin chain, restoring β-globin expression and reactivating γ-globin expression, leading a reduced disease severity, treatment necessity, treatment interval, and disease complications, thus, increasing the life quality of the patients and alleviating economic burden. Therefore, nucleic acid-based therapy might become a potential targeted therapy for β-thalassemia.

Gene therapies for transfusion dependent β-thalassemia: Current status and critical criteria for success

Thalassemia is one of the most prevalent monogenic diseases usually caused by quantitative defects in the production of β-globin leading to severe anemia. Technological advances in genome sequencing, stem cell selection, viral vector development, transduction and gene editing strategies now allow for efficient exvivo genetic manipulation of human stem cells that can lead to production of hemoglobin, leading to a meaningful clinical benefit in thalassemia patients. In this review, the status of the gene-therapy approaches available for transfusion dependent thalassemia are discussed, along with the critical criteria that affect efficacy and lessons that have been learned from the early phase clinical trials. Salient steps necessary for the clinical development, manufacturing, and regulatory approvals of gene therapies for thalassemia are also highlighted, so that the potential of these therapies can be realized. It is highly anticipated that gene therapies will soon become a treatment option for patients lacking compatible donors for hematopoietic stem cell transplant and will offer an alternative for definitive treatment of β-thalassemia.

The Development and Application of a Base Editor in Biomedicine

Using a base editor to generate monogenic disease models and correct pathogenic point mutations is a breakthrough technology for exploration and treatment of human diseases. As a burgeoning approach for genomic modification, the fused CRISPR/Cas9 with various deaminase separately has significantly increased the efficiency of producing a precise point mutation with minimal insertions or deletions (indels). Along with the flexibility and efficiency, a base editor has been widely used in many fields. This review discusses the recent development of a base editor, including evolution and advance, and highlights the applications and challenges in the field of gene therapy. Depending on rapid improvement and optimization of gene editing technology, the prospect of base editor is immeasurable.

Cardiorenal syndrome in thalassemia patients

Background

Cardiorenal syndrome (CRS), a serious condition with high morbidity and mortality, is characterized by the coexistence of cardiac abnormality and renal dysfunction. There is limited information about CRS in association thalassemia. This study aimed to investigate the prevalence of CRS in thalassemia patients and also associated risk factors.

Methods

Thalassemia patients who attended the out-patient clinic of a tertiary care university hospital from October 2016 to September 2017 were enrolled onto this cross-sectional study. Clinical and laboratory findings from 2 consecutive visits, 3 months apart, were assessed. The criteria for diagnosis of CRS was based on a system proposed by Ronco and McCullough. Cardiac abnormalities are assessed by clinical presentation, establishment of acute or chronic heart failure using definitions from 2016 ESC guidelines or from structural abnormalities shown in an echocardiogram. Renal dysfunction was defined as chronic kidney disease according to the 2012 KDIGO guidelines.

Results

Out of 90 thalassemia patients, 25 (27.8%) had CRS. The multivariable analysis showed a significant association between CRS and extramedullary hematopoiesis (EMH) (odds ratio (OR) 20.55, p = 0.016); thalassemia type [β⁰/β^E vs β⁰/β⁰ thalassemia (OR 0.005, p = 0.002)]; pulmonary hypertension (OR 178.1, p = 0.001); elevated serum NT-proBNP (OR 1.028, p = 0.022), and elevated 24-h urine magnesium (OR 1.913, p = 0.016). There was no association found between CRS and frequency of blood transfusion, serum ferritin, liver iron concentration, cardiac T2*, type of iron chelating agents, or urine neutrophil gelatinase-associated lipocalin level.

Conclusions

CRS is relatively common in thalassemia patients. Its occurrence is associated with laboratory parameters which are easily measured in clinical practice.

Mutation spectrum and erythrocyte indices characterisation of α-thalassaemia and β-thalassaemia in Sichuan women in China: a thalassaemia screening survey of 42 155 women

AIMS

The present study aims to investigate the mutation spectrum of thalassaemia, and characterise the erythrocyte indices of thalassaemia in a large cohort in Sichuan, which is a province with a high prevalence of thalassaemia in southern China.

METHODS

The present study was conducted from July 2017 to July 2019. A total of 42 155 women screened for thalassaemia were enrolled. The thalassaemia carriers were screened by erythrocyte analysis and haemoglobin electrophoresis. Then, the screening test results and genetic results were collected.

RESULTS

A total of 1109 individuals had thalassaemia gene defects. Among these individuals, 69.7% were α-thalassaemia (α-thal) and 28.6% were β-thalassaemia (β-thal). For α-thal defects, carriers with ^--SEA had the lowest mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) values. For β-thal defects, carriers with heterozygous haemoglobin E and -28 had the highest MCV and MCH values. In addition, an MCV cut-off of 80 fl and an MCH cut-off of 27 pg was able to detect 99.1% α0 thalassaemia and 99.7% β0/β+ thalassaemia; however, that criterion could result in a great number of false-negative results in α+ carriers.

CONCLUSION

A criterion of MCV <80 fl and MCH <27 pg is recommended for detecting -SEA carriers and β0/β+ carriers, while higher cut-offs are needed to detect α+ carriers.

Development of DNA controls for detection of β-thalassemia mutations commonly found in Asian

INTRODUCTION

Several DNA-based approaches including a reverse dot-blot hybridization (RDB) have been established for detection of β-thalassemia genotypes to provide accurate genetic counseling and prenatal diagnosis for prevention and control of severe β-thalassemia. However, one of major concerns of these techniques is a risk of misdiagnosis due to a lack of DNA controls. Here, we constructed positive DNA controls for β-thalassemia genotyping in order to ensure that all steps in the analysis are performed properly.

METHODS

Four recombinant β-globin plasmids, including a normal sequence and three different mutant panels covering 10 common β-thalassemia mutations in Asia, were constructed by a conventional cloning method followed by sequential rounds of site-directed mutagenesis. These positive DNA controls were further validated by RDB analysis.

RESULTS

We demonstrated the applicability of established positive DNA controls for β-thalassemia genotyping in terms of accuracy and reproducibility by RDB analysis. We further combined three mutant β-globin plasmids into a single positive control, which showed positive signals for both normal and mutant probes of all tested mutations. Therefore, only two positive DNA controls, normal and combined mutant β-globin plasmids, are required for detecting 10 common β-thalassemia mutations by RDB, reducing the cost, time, and efforts in the routine diagnosis.

CONCLUSION

The β-globin DNA controls established here provide efficient alternatives to a conventional DNA source from peripheral blood, which is more difficult to obtain. They also provide a platform for future development of β-globin plasmid controls with other mutations, which can also be suitable for other DNA-based approaches.

Genotypic groups as risk factors for cardiac magnetic resonance abnormalities and complications in thalassemia major: a large, multicentre study

BACKGROUND

The causes and effects of genotypic heterogeneity in beta-thalassemia major (β-TM) have not been fully investigated. The aim of this multicentre study was to determine whether different genotype groups could predict the development of cardiovascular magnetic resonance abnormalities and cardiac complications.

MATERIALS AND METHODS

We considered 708 β-TM patients (373 females, age 30.05±9.47 years) consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) network. Data were collected from birth to the first cardiac magnetic resonance scan. Myocardial iron overload was assessed using a T2* technique. Biventricular function was quantified by cine images. Macroscopic myocardial fibrosis was evaluated by a late gadolinium enhancement technique.

RESULTS

Three groups of patients were identified: β⁺ homozygotes (n=158), β⁺/β° heterozygotes (n=298) and β° homozygotes (n=252). Compared to β⁺ homozygotes, the other two groups showed a significantly higher risk of myocardial iron overload and left ventricular dysfunction. We recorded 90 (13.0%) cardiac events: 46 episodes of heart failures, 38 arrhythmias (33 supraventricular, 3 ventricular and 2 hypokinetic) and 6 cases of pulmonary hypertensions. β° homozygotes showed a significantly higher risk than β⁺ homozygotes of arrhythmias and cardiac complications considered globally.

DISCUSSION

Different genotype groups predicted the development of myocardial iron overload, left ventricular dysfunction, arrhythmias and cardiac complications in β-TM patients. These data support the importance of genotype knowledge in the management of β-TM patients.

Development of the Next Generation Sequencing-Based Diagnostic Test for β-Thalassemia and its Validation in a Pashtun Family

β-Thalassemia (β-thal) is a common monogenic disease with ethnic-specific mutations on the HBB gene throughout the world. The reported mutations either reduce the expression or completely inactivate the HBB gene. In Pakistan, the prevalence of β-thal is high due to consanguineous marriages. Accurate identification of mutations in carriers is imperative for prevention of β-thal in subsequent generations. To overcome the limitations of traditional testing methods for β-thal, a next-generation sequencing (NGS)-based diagnostic test was designed and validated by sequencing the entire HBB gene. The primer set covering the entire HBB gene was designed and validated in a Pashtun β-thalassemic family. The polymerase chain reaction (PCR) product was sequenced using an Illumina MiSeq platform. A homozygous pathogenic insertion of A>AC/AC (rs35699606) was detected in an affected member of the family, while unaffected members were heterozygous for it. In addition, all family members were homozygous for the synonymous variant, A>G/G (rs713040), except the father who was heterozygous for it. We sequenced the entire HBB gene using the NGS-based test, which is highly sensitive, robust and specific for the diagnosis and screening of β-thal in Pakistan, especially for families practicing consanguineous marriages.

Hematological Characteristics of β-Globin Gene Mutation -50 (G>A) (HBB: c.-100G>A) Carriers in Mainland China

The -50 (G>A) (HBB: c.-100G>A) mutation was first reported as a β-thalassemia (β-thal) allele in a Chinese family. However, the hematological features of carriers with this variant are not available. In this study, we present the hematological data associated with -50 (G>A) to determine its phenotype. During a 4-year period, eight simple heterozygotes and three double heterozygotes for the -50 mutation and α-thalassemia (α-thal) were included. The simple heterozygotes had normal hematological parameters. The double heterozygotes had the hematological findings of simple α-thal heterozygotes. Two subjects with a compound heterozygosity for -50 and β-thal were also found, and both had typical hematological parameters of β-thal trait. Therefore, we present evidence that -50 (G>A) is likely a silent β-thal allele. Compound heterozygotes for -50/β-thal had no phenotype of severe β-thal. This information might be helpful in genetic counseling for couples in thalassemia high-prevalence areas.

An Innovative Multilevel Test for Hemoglobinopathies: TGA/Chemometrics Simultaneously Identifies and Classifies Sickle Cell Disease From Thalassemia

Introduction: Hemoglobinopathies are the most common genetic disorder wordlwide and because of migrations are become an emerging global health problem. Screening programmes for Sickle cell disease and Thalassemia have been implemented in some countries, but are not a common practice, due to a lack in the accuracy of the methods and to the costs of the analyses. Objectives: The objective of this study was the application of the thermogravimetry coupled to chemometrics as new screening method to perform an early diagnosis of thalassemia and sickle cell disease. Methods: Whole blood samples (30 μL) from sickle cell anemia and thalassemia patients were analyzed using the thermobalance TG7 and the resulting curves were compared with those of healthy individuals. A chemometric approach based on Principal Components Analysis (PCA) was exploited to enhance correlation between thermogravimetric profiles and a model of prediction by Partial Least Square Discriminant Analysis (PLS-DA) was developed and validated. Results: The characteristic profile of the blood sample thermal decomposition and the first derivative of the TG curve showed that patients were clearly distinguished from healthy individuals as a result of different amounts of water and corpuscular fraction of blood. The chemometric approach based on PCA allowed a quick identification of differences between healthy subjects and patients and also between thalassemic and sickle cell anemia subjects. Chemometric tools (PLS-DA) were used to validate a model of prediction to process the thermogravimetric curves and to obtain in 1 h an accurate diagnosis. The TGA/Chemometric test permitted to perform first level test for hemoglobinopathies with the same accuracy of confirmatory analyses obtained by the molecular investigation. Conclusions: A screening test based on the coupling of thermogravimetry and chemometrics was optimized for the differential diagnosis of hemoglobinopathies. The novel test is able to simultaneously perform a simple and fast diagnosis of sickle cell anemia or thalassemia, in a single analysis of few microliters of non-pretreated whole blood at low cost, and with high accuracy. Moreover this method results particularly suitable in pediatric patients as it requires small sample volumes and is able to characterize also transfused patients.

β-Globin Gene Mutations in Pediatric Patients with β-Thalassemia in the Region of Çukurova, Turkey

β-Thalassemia (β-thal) is one of the most common genetic disorders in Turkey. In this study, we investigated the mutations and frequency of β-thal at the molecular level in pediatric β-thal patients in the Çukurova region. The β-thal mutations of 52 cases were analyzed. An automated blood cell counter was used for hematological data. Cellulose acetate electrophoresis and high performance liquid chromatography (HPLC) methods were used for hemoglobin (Hb) typing. Amplification refractory mutation system (ARMS), restriction fragment length polymorphism (RFLP), gap-polymerase chain reaction (gap-PCR) and DNA sequencing analysis methods were used to determine genomic features. In this study, we found that 36 subjects carried homozygous mutations [IVS-I-110 (G>A) (HBB: c.93-21G>A) (58.3%), codon 8 (-AA) (HBB: c.25_26delAA) (5.6%), -30 (T>A) (HBB: c.-80T>A) (5.6%), IVS-I-6 (T>C) (HBB: c.92+6T>C) (5.6%) and IVS-II-1 (G>A) (HBB: c.315+1G>A) (5.6%)]. We found that 13 subjects carried compound heterozygosities for IVS-I-110/IVS-I-6 (15.4%) and IVS-I-110/frameshift codon (FSC) 44 (-C) (HBB: c.135delC) (15.4%). We observed that the Syrian subject also carried a compound heterozygosity for IVS-I-6/IVS-I-25 (-25 bp) (HBB: c.93_21del). We determined that the most frequently observed β-thal mutation in the Çukurova region, where various types of hemoglobinopathies have been observed, is the IVS-I-110 mutation. As the prevalence of the disease will affect the region where the immigrant population is dense, population screening and prenatal diagnosis (PND) should be increased and the public should be made aware of the consequences.

Serum folate and cytokines in heterozygous β-thalassemia

INTRODUCTION

Folate deficiency is commonly reported in β-thalassemia. Individuals heterozygous for β-thalassemia may have higher folate requirements than normal individuals.

OBJECTIVES

To document the concentration of serum total folate and its forms in β-thalassemia heterozygote users (β-TmU) and nonusers (β-TmN) of 5 mg folic acid/d; to determine whether folic acid (FA) consumption from fortified foods allows beta-Tm patients, who do not take FA supplements, to meet their dietary folate requirements; and to investigate the association between higher serum unmetabolized folic acid (UMFA) and inflammatory cytokine concentrations.

METHODS

Serum total folate and forms were measured in 42 β-Tm (13 β-TmU and 29 β-TmN) and 84 healthy controls. The mononuclear leucocyte mRNA expression of relevant genes and their products and hematological profiles were determined.

RESULTS

β-TmU had higher serum total folate, 5-methyltetrahydrofolate, UMFA, and tetrahydrofolate (THF) compared with β-TmN. The β-TmN had lower serum total folate and THF than controls. Plasma total homocysteine (tHcy) was lower in β-TmU compared with both β-TmN and controls, while β-TmN had higher tHcy than controls. β-TmU had higher IL-8 than their controls while β-TmN had higher IL-6 and IL-8 than their controls. β-TmU have higher levels of serum total folate, 5- methyltetrahydrofolate, UMFA, and THF than controls. There was no association between UMFA concentrations and cytokine levels.

CONCLUSIONS

Mandatory flour fortification with FA in Brazil may be insufficient for β-TmN, since they have higher tHcy and lower serum total folate than controls. Furthermore, β-TmN have higher IL-6 levels than β-TmU. UMFA was not associated with inflammatory cytokine levels.

Determination of mutations in iron regulating genes of beta thalassemia major patients of Khyber Pakhtunkhwa, Pakistan

Background

Hepcidin and hemochromatosis (HFE) are iron regulatory proteins that are encoded by HAMP and HFE genes. Mutation in either HAMP gene or HFE gene causes Hepcidin protein deficiency that can lead to iron overload in beta thalassemia patients. The aim of this research work was to study the presence of G71D mutation of HAMP gene and H63D mutation of HFE gene in beta thalassemia major and minor group to check the association of these mutations with serum ferritin level of beta thalassemia patients.

Methods

The study was conducted on 42 beta thalassemia major and 20 beta thalassemia minor samples along with 20 control samples. The genotyping of both mutations has done by ARM‐PCR technique with specific set of primers.

Results

Significant effect of G71D and H63D mutations was observed on serum ferritin level of thalassemia major group. The risk allele of HAMP G71D and HFE H63D was found with high frequency (48% and 49%, respectively) in beta thalassemia major than in control group. High genotypic frequency of HAMP and HFE gene mutation gene mutation was observed in beta thalassemia major than beta thalassemia minor and control group (7% and 9%, respectively).

Conclusion

It can be concluded that both HAMP and HFE gene mutations show high frequency in beta thalassemia major patients and mean significant association between mutations and high serum ferritin level of beta thalassemia major patients but the nonsignificant results of Odd ratios showed that both mutations do not act as major risk factor in beta thalassemia major.

The First Asian, Single-Center Experience of Blastocyst Preimplantation Genetic Diagnosis with HLA Matching in Thailand for the Prevention of Thalassemia and Subsequent Curative Hematopoietic Stem Cell Transplantation of Twelve Affected Siblings

RESULTS

In 221 cycles from 138 patients (104 cycles requiring HLA matching), 90.5% had embryo(s) biopsied for genetic testing. There were 119 embryo transfers for thalassemia (76) and thalassemia-HLA cases (43), respectively, resulting in overall clinical pregnancy rates of 54.6%, implantation rates of 45.7%, and live birth rates of 44.1%. Our dataset included fifteen PGD-HLA live births with successful HSCT in twelve affected siblings, 67% using umbilical cord blood stem cells (UCBSC) as the only SC source.

CONCLUSIONS

We report favorable thalassemia PGD and PGD-HLA laboratory and clinical outcomes from a single center. The ultimate success in PGD-HLA is of course the cure of a thalassemia-affected sibling by HSCT. Our PGD-HLA HSCT series is the first and largest performed entirely in Asia with twelve successful and two pending cures and predominant UCBSC use.

Noninvasive prenatal diagnosis for pregnancies at risk for β-thalassaemia: a retrospective study

OBJECTIVE

To evaluate the clinical feasibility of noninvasive prenatal diagnosis (NIPD) for β-thalassaemia using circulating single molecule amplification and re-sequencing technology (cSMART).

DESIGN

Through carrier screening, 102 pregnant Chinese couples carrying pathogenic HBB gene variants were recruited to the study. Pregnancies were managed using traditional invasive prenatal diagnosis (IPD). Retrospectively, we evaluated the archived pregnancy plasma DNA by NIPD to evaluate the performance of our cSMART assay for fetal genotyping.

SETTING

Chinese prenatal diagnostic centres specialising in thalassaemia testing.

POPULATION

Chinese carrier couples at high genetic risk for β-thalassaemia.

METHODS

Fetal cell sampling was performed by amniocentesis and HBB genotypes were determined by reverse dot blot. NIPD was performed by a newly designed HBB cSMART assay and fetal genotypes were called by measuring the allelic ratios in the maternal cell-free DNA.

MAIN OUTCOME MEASURES

Concordance of HBB fetal genotyping between IPD and NIPD and the sensitivity and specificity of NIPD.

RESULTS

Invasive prenatal diagnosis identified 29 affected homozygotes or compound heterozygotes, 54 heterozygotes and 19 normal homozygotes. Compared with IPD results, 99 of 102 fetuses (97%) were correctly genotyped by our NIPD assay. Two of three discordant samples were false positives and the other sample involved an incorrect call of a heterozygote carrier as a homozygote normal. Overall, the sensitivity and specificity of our NIPD assay was 100% (95% CI 88.06-100.00%) and 97.26% (95% CI 90.45-99.67%), respectively.

CONCLUSIONS

This study demonstrates that our cSMART-based NIPD assay for β-thalassaemia has potential clinical utility as an alternative to IPD for pregnant HBB carrier couples.

TWEETABLE ABSTRACT

A new noninvasive test for pregnancies at risk for β-thalassaemia.

Enabling routine β-thalassemia Prevention and Patient Management by scalable, combined Thalassemia and Hemochromatosis Mutation Analysis

BACKGROUND

Beta (β)-thalassemia is one of the most common inherited disorders worldwide, with high prevalence in the Mediterranean, the Middle East and South Asia. Over the past 40 years, awareness and prevention campaigns in many countries have greatly reduced the incidence of affected child births. In contrast, much remains to be done in South-Asia. Thus, for Pakistan, an estimated ~ 7000 children annually are born with thalassemia, with no sign of improvement. Although there is good agreement that intermarriage of carriers significantly contributes to the high prevalence of the disorder, effective tools for molecular screening and diagnosis on which to base prevention programs are not readily available.

METHODS

Here, we present results for a novel LeanSequencing™ process to identify a combination of 18 β-thalassemia mutations (including the sickle cell anemia mutation, HbS, and structural variants HbC and HbE) and 2 hemochromatosis mutations in a multi-ethnic population of 274 pediatric and adolescent patients treated at Afzaal Memorial Thalassemia Foundation in Karachi, Pakistan.

RESULTS

We found substantial differences in the predominance of disease-causing mutations among the principal ethnic groups in our cohort. We also found the hemochromatosis mutation H63D C > G in 61 (or 22.1%) of our patients including 6 (or 2.2%) homozygotes.

CONCLUSIONS

To our knowledge, this is the first screen combining a large set of β-thalassemia and hemochromatosis mutations, so as to facilitate the early identification of patients who may be at increased potential risk for complications from iron overload and thereby to improve the prospective management of thalassemia patients.

Multiplex precise base editing in cynomolgus monkeys

Common polygenic diseases result from compounded risk contributed by multiple genetic variants, meaning that simultaneous correction or introduction of single nucleotide variants is required for disease modeling and gene therapy. Here, we show precise, efficient, and simultaneous multiplex base editing of up to three target sites across 11 genes/loci in cynomolgus monkey embryos using CRISPR-based cytidine- and adenine-base editors. Unbiased whole genome sequencing demonstrates high specificity of base editing in monkey embryos. Our data demonstrate feasibility of multiplex base editing for polygenic disease modeling in primate zygotes.

Red blood cell consumption in a large cohort of patients with thalassaemia: a retrospective analysis of main predictors

The phenotype/genotype relationship of patients with transfusion-dependent thalassaemia (TDT) is particularly complex and variable, thus generating different levels of severity and of annual transfusion volume (ATV). In this study, we explored the role and the contribution of several factors potentially involved in determining mean ATV in a cohort of TDT patients which have been followed since long time. We collected data on one-hundred and twenty-seven patients with transfusion-dependent β-thalassaemia followed at Rare Blood Cell Disease Unit, AORN Cardarelli Hospital. Age at first transfusion, genotype, spleen status (splenectomy or not), and mean soluble transferrin receptor (sTfR) were the parameters included in the analysis. At stepwise regression analysis which included all the parameters, only splenectomy and mean sTfR significantly predicted the mean ATV (F = 70.94, P < 0.0001, R² = 0.540). Overall, our data may suggest that in patients with TDT, the measurement of sTfR level together with the spleen status could contribute, more accurately than genotype, to provide a basal evaluation of residual erythropoietic activity and mean ATV.

Hypoparathyroidism in a Case of Transfusion Dependent Thalassemia

Repeated blood transfusions in transfusion dependent thalassemia (TDT) leads to iron overload-related endocrine complications. Hypoparathyroidism (HPT) with severe signs of hypocalcemia is a recognized complication among these patients.

A 14-year-old thalassaemic boy, on regular transfusion and on anticonvulsant therapy with a presumptive diagnosis of epilepsy for the last 1 year, was admitted with high fever and severe muscle cramps with positive Trousseau’s sign. He was diagnosed as a case of primary HPT and magnesium deficiency on the basis of low serum calcium, high phosphate, normal alkaline phosphates, very low intact parathyroid hormone (iPTH), normal serum vitamin D and very low serum magnesium level. His calcium, magnesium and phosphate level normalised following treatment with intravenous magnesium and calcium. His iPTH improved but remained at low normal. He was discharged from hospital with oral calcium, calcitriol, and magnesium supplementation. The anticonvulsant (Phenobarbitone) was successfully withdrawn gradually over the next six months without any recurrence of seizure in the subsequent 3 years of follow up.

Acquired HPT (apparently from hemosiderosis) is a common cause of hypocalcemia; and magnesium depletion further complicated the situation leading to severe hypocalcemia with recurrent episodes of convulsion. Magnesium replacement improved the parathyroid hormone (PTH) value proving its role in acquired HPT. Very high phosphate level on admission and poor PTH response with respect to the low serum calcium, indicates intrinsic parathyroid pathology. Metabolic abnormalities should always be evaluated in thalassaemic subject with seizure disorder and it appears that the initial convulsive episodes were due to hypocalcemia.

Muscle pain, cramps or convulsion may occur from HPT and simultaneous magnesium deficiency in transfusion dependent thalassaemic subjects. Metabolic correction is more important than anticonvulsant medication. Calcium and magnesium should both be assessed routinely in transfusion dependent thalassemic patients.

Deletional Alpha-Thalassemia Alleles in Amazon Blood Donors

Alpha-thalassemia is highly prevalent in the plural society of Brazil and is a public health problem. There is limited knowledge on its accurate frequency and distribution in the Amazon region. Knowing the frequency of thalassemia and the prevalence of responsible mutations is, therefore, an important step in the understanding and control program. Hematological and molecular data, in addition to serum iron and serum ferritin, from 989 unrelated first-time blood donors from Amazonas Hemotherapy and Hematology Foundation (FHEMOAM) were collected. In this study, the subjects were screened for -α ^3.7/4.2/^20.5, -^SEA, -^FIL, and -^MED deletions. Alpha-thalassemia screening was carried out between 2016 and 2017 among 714 (72.1%) male and 275 (27.9%) female donors. The aims of this analysis were to describe the distribution of various alpha-thalassemia alleles by gender, along with their genotypic interactions, and to illustrate the hematological changes associated with each phenotype. Amongst the patients, 5.35% (n = 53) were diagnosed with deletion -α ^-3.7 and only one donor with α ^-4.2 deletion. From the individuals with -α ^-3.7, 85.8% (n = 46) were heterozygous and 14.20% (n = 7) were homozygous. The frequency of the -α ^-3.7 deletion was higher in male (5.89%) than in female (4.0%). There is no significant difference in the distribution of -α ^-3.7 by gender (p = 0.217). The -α ^20.5, -^SEA, and -^MED deletions were not found. All subjects were analyzed for serum iron and serum ferritin, with 1.04% being iron deficient (n = 5) and none with very high levels of stored iron (>220 µg/dL). Alpha-thalassemia-2^3.7kb deletion was the most common allele detected in Manaus blood donors, which is a consistent result, once it is the most common type of α-thalassemia found throughout the world. As expected, the mean of hematological data was significantly lower in alpha-thalassemia carriers (p < 0.001), mainly homozygous genotype. Leukocytes and platelet count did not differ significantly. Due to the small number of individuals with iron deficiency found among blood donors, the differential diagnosis between the two types of anemia was not possible, even because minor changes were found among hematological parameters with iron deficiency and α-thalassemia. Despite this, the study showed the values of hematological parameters, especially MCV and MCH, are lower in donors with iron deficiency, especially when associated with α-thalassemia, and therefore, it may be useful to discriminate different types of microcytic anaemia. In conclusion, we believed screening for thalassemia trait should be included as part of a standard blood testing before blood donation. It should be noted that this was the first study to perform the screening for alpha deletions in blood donors from the Manaus region, and further studies are required to look at the effects of donated thalassemic blood.

Interfacial energy driven distinctive pattern formation during the drying of blood droplets

HYPOTHESIS

Dried blood droplet morphology may potentially serve as an alternative biomarker for several patho-physiological conditions. The deviant properties of the red blood cells and the abnormal composition of diseased samples are hypothesized to manifest through unique cell-cell and cell-substrate interactions leading to different morphological patterns. Identifying distinctive morphological trait from a large sample size and proposing confirmatory explanations are necessary to establish the signatory pattern as a potential biomarker to differentiate healthy and diseased samples.

EXPERIMENTS

Comprehensive experimental investigation was undertaken to identify the signatory dried blood droplet patterns. The corresponding image based analysis was in turn used to differentiate the blood samples with a specific haematological disorder "Thalassaemia" from healthy ones. Relevant theoretical analysis explored the role of cell-surface and cell-cell interactions pertinent to the formation of the distinct dried patterns.

FINDINGS

The differences observed in the dried blood patterns, specifically the radial crack lengths, were found to eventuate from the differences in the overall interaction energies of the system. A first-generation theoretical analysis, with the mean field approximation, also confirmed similar outcome and justified the role of the different physico-chemical properties of red blood cells in diseased samples resulting in shorter radial cracks.

Probability of change in life: Amino acid changes in single nucleotide substitutions

Mutations underpin the processes in life, be it beneficial or detrimental. While mutations are assumed to be random in the bereft of selection pressures, the genetic code has underlying computable probabilities in amino acid phenotypic changes. With a wide range of implications including drug resistance, understanding amino acid changes is important. In this study, we calculated the probabilities of substitutions mutations in the genetic code leading to the 20 amino acids and stop codons. Our calculations reveal an enigmatic in-built self-preserving organization of the genetic code that averts disruptive changes at the physicochemical properties level. These changes include changes to start, aromatic, negative charged amino acids and stop codons. Our findings thus reveal a statistical mechanism governing the relationship between amino acids and the universal genetic code.

Correlation of Cardiac and Liver Iron Level with T2*MRI and Vitamin D3 Serum Level in Patients with Thalassemia Major

Introduction

Thalassemia is a hypochromic microcytic anemia, which is characterized by congenital disorders. In thalassemia patients, bone diseases are one of the causes of mortality. Our goal was to investigate the association between vitamin D deficiency and increased iron uptake by cardiac myocytes and hepatocytes.

Materials and Methods

Forty patients with thalassemia major were studied in Amir Kabir Hospital, Arak, Iran. The information obtained through clinical examination. Serum ferritin level was determined by ELISA and T2*MRI performed for measuring iron content in the heart and the liver.

Results

The average age of the patients was 23.8 ± 10.7 years. The mean T2*MRI values were 23.7 ± 7. The vitamin D3 level in 33 patients (82.5% cases) was less than 20 ng/dl, 2 patients (5%) in the range of 20-30 ng/dl, and the others had above 30 ng/dl. Correlation between vitamin D and age was 0.611. Correlation coefficient between heart and liver T2*MRI with ferritin level in patients was 0.437 and 0.335, respectively.

Conclusion

Due to significant associations, the periodic measurement of vitamin D, as well as PTH, is recommended for patients with thalassemia major.

The Incidence of Minor β-thalassemia Among Individuals Participated in Premarital Screening Program in Ardabil Province: North-west of Iran

Introduction:

The most effective way to prevent thalassemia is to screen for the disease at the population level and then to evaluate the molecularity of individuals. Considering the importance of minor β-thalassemia and its high prevalence in societies.

Aim:

to investigate the incidence of minor β-thalassemia among Individuals participated in Premarital Screening Program in Ardabil province: North-west of Iran.

Methods:

This descriptive cross-sectional study was conducted on 39620 individuals participated in the national screening program for Minor β-Thalassemia. Of them 1925 cases had mean corpuscular volume (MCV) < 80 in one person or couple which referred to HbA2 concentration check.

Results:

Of all 1925 cases, 95 cases (4.93%) had HbA2>3.5 and defined as Minor β-Thalassemia. The total incidence of minor β-thalassemia among all participated people was 2.4%. Of thalassemia cases 48.4% were women and 51.6% were men. Of all β-thalassemia cases, 49.5% live in Ardabil city and rest of them live in other cities.

Conclusion:

Results showed that the prevalence of minor β-thalassemia in Ardabil province was lower than country average rate and a study should be done in future for exact estimation of the disease.

Screening Readthrough Compounds to Suppress Nonsense Mutations: Possible Application to β-Thalassemia

Several types of thalassemia (including β⁰39-thalassemia) are caused by nonsense mutations in genes controlling globin production, leading to premature translation termination and mRNA destabilization mediated by the nonsense mediated mRNA decay. Drugs (for instance, aminoglycosides) can be designed to suppress premature translation termination by inducing readthrough (or nonsense suppression) at the premature termination codon. These findings have introduced new hopes for the development of a pharmacologic approach to cure this genetic disease. In the present review, we first summarize the principle and current status of the chemical relief for the expression of functional proteins from genes otherwise unfruitful for the presence of nonsense mutations. Second, we compare data available on readthrough molecules for β⁰-thalassemia. The examples reported in the review strongly suggest that ribosomal readthrough should be considered as a therapeutic approach for the treatment of β⁰-thalassemia caused by nonsense mutations. Concluding, the discovery of molecules, exhibiting the property of inducing β-globin, such as readthrough compounds, is of great interest and represents a hope for several patients, whose survival will depend on the possible use of drugs rendering blood transfusion and chelation therapy unnecessary.

Optical coherence tomography angiography findings in young β-thalassemia patients

PURPOSE

The purpose was to evaluate retinal vascular parameters by optical coherence tomography angiography in β-thalassemia major patients.

METHODS

Thirty-three patients with β-thalassemia major (study group) and 29 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. The mean foveal avascular zone, non-flow area, foveal avascular zone perimeter, acircularity index of foveal avascular zone, foveal density, the superficial capillary plexus, and deep capillary plexus were scanned using 6 × 6 mm optical coherence tomography angiography scans centered on the macula. Superficial capillary plexus and deep capillary plexus were also scanned centered on the optic disk. We collected data on histories of patients, and hemoglobin and ferritin were also studied from both groups.

RESULTS

The mean age was 13.85 ± 4.69 years (range: 4-21 years) in β-thalassemia major group and 12.59 ± 3.66 years (range: 6-18 years) in the control group. The mean foveal avascular zone value was 0.265 ± 0.11 mm² in the study group and 0.296 ± 0.12 mm² in the control group. The mean non-flow area value was 0.468 ± 0.12 mm² in the study group and 0.479 ± 0.14 mm² in the control group (p > 0.05). Differences in the mean values for foveal density and acircularity index were statistically significant between the study group and control group (p < 0.05, p = 0.026, and p = 0.026, respectively). Superficial capillary plexus and deep capillary plexus were not a significant difference between the study and control groups in 6 × 6 mm scans on macula and 4.5 × 4.5 mm scans on optic disk area (p > 0.05). Acircularity index was negatively correlated (r = -0.292, p = 0.026), and foveal density was positively correlated with hemoglobin (r = 0.292, p = 0.026).

CONCLUSION

By using optical coherence tomography angiography, we detected foveal microvascular changes in young β-thalassemia patients before significant ocular anomalies development.

Thalassemia: Common Clinical Queries in Management

Beta thalassemia major (TM) is the most frequent form of transfusion-dependent inherited anemia in India. The thalassemia syndromes exhibit enormous variability in their genetic basis and phenotypic expression. The authors recommend that the diagnosis of TM or non-transfusion-dependent thalassemia (NTDT) should not be based on a one-time assessment. Many patients have a chronic anemia that is not severe enough to justify regular transfusions, but the clinical course can evolve with age. Continued observation may reveal that some patients who are considered NTDT will benefit from transfusions later in life. Clinical decision making can be influenced by the perceived difficulty in access to a safe blood supply and the cost of therapy. Here, authors present selected case scenarios that address common issues in the management of TM or NTDT. The recommendations are based on published evidence where available or on the authors' shared experience. Among the topics under discussion are deciding when to start regular transfusions, the role of hydroxyurea in TM, the procedure for blood administration, the use of deferasirox for chelation and monitoring of side effects, the role of splenectomy, and the prospects for gene therapy. In order to achieve an optimal outcome with blood transfusions and chelation therapy over the lifetime, it is essential to adhere to the current guidelines for the management of thalassemia.

Oral ferroportin inhibitor VIT-2763: First-in-human, phase 1 study in healthy volunteers

Restriction of iron availability by ferroportin inhibition is a novel approach to treating non‐transfusion‐dependent thalassemia (β‐thalassemia intermedia). This first‐in‐human, Phase I study (https://www.clinicaltrialsregister.eu; EudraCT no. 2017‐003395‐31) assessed the safety, tolerability, pharmacokinetics and pharmacodynamics of single‐ and multiple‐ascending doses (SAD and MAD) of the oral ferroportin inhibitor, VIT‐2763, in healthy volunteers. Participants received VIT‐2763 5/15/60/120/240 mg or placebo in the SAD phase and VIT‐2763 60/120 mg once daily, VIT‐2763 60/120 mg twice daily, or placebo for 7 days in the MAD phase. Seventy‐two participants completed treatment. VIT‐2763 was well tolerated and demonstrated a similar safety profile to the placebo. There were no serious or severe adverse events, or discontinuations due to adverse events. VIT‐2763 absorption was relatively fast, with detectable levels 15 to 30 minutes post‐dose. Following multiple dosing there was no apparent change in absorption and accumulation was minimal. Mean elimination half‐life was 1.9 to 5.3 hours following single dosing, and 2.1 to 3.8 hours on Day 1 and 2.6 to 5.3 hours on Day 7, following repeated dosing. There was a temporary decrease in mean serum iron levels with VIT‐2763 single doses ≥60 mg and all multiple doses; mean calculated transferrin saturation (only assessed following multiple dosing) also temporarily decreased. A shift in mean serum hepcidin peaks followed administration of all iron‐lowering doses of VIT‐2763. This effect was less pronounced after 7 days of multiple dosing (aside from with 120 mg once daily). These results support the initiation of clinical studies in patients with non‐transfusion‐dependent thalassemia and documented iron overload due to ineffective erythropoiesis.

Identification of seven novel variants in the β-globin gene in transfusion-dependent and normal patients

INTRODUCTION

Abnormality in HBB results in an inherited recessive blood disorder, which can be caused by variants at the transcriptional or translational level affecting the stability and the production of the HBB chain. The severity of the disease relies on the variant's characteristics. This study aimed to identify the common β-globin HBB variants in the population of the Eastern Province, which has the highest prevalence of blood diseases in Saudi Arabia.

MATERIAL AND METHODS

Direct sequence of β-globin HBB gene, and alpha-globin HBA1 and HBA2 genes was performed on a total of 545 blood samples (transfusion-dependent: 215, 106 men and 109 women; normal healthy subjects: 330, 197 men and 133 women) collected from Saudi Arabian participants in the Eastern region.

RESULTS

A total of 36 variants in HBB gene were revealed with 11 variants that have been reported for the first time in Saudi Arabia, including 7 novel variants that have been identified for the first time in HBB gene. The novel variants consisted of two exonic (HBB:c.252C>T; HBB:c.281G>T) and five intronic variants (c.316-183_316-168del; c.315+241T>A; c.315+376T>C; c.316-114C>G; c.315+208T>G) at HBB gene. The novel exonic variants and three (c.316-183_316-168del; c.315+241T>A; c.315+376T>C) intronic variants were co-inherited with α deletion.

CONCLUSIONS

This current study updated the HBB gene variations with newly identified variants of HBB gene and co-inheritance with α-globin deletions. The identified β-globin mutations will strengthen the genetic reference that could aid in characterizing mutations that are associated with phenotype of thalassemia in a specific region.

Clinical Laboratory Manifestation and Molecular Diagnosis of β-Thalassemia Patients in Iraq

Many studies determined the demographic and ethnic border of patients with beta (β)-thalassemia mutations and their migration. The effective way to health care policy of β-thalassemia is to prevent homozygote births and reduce the severity of the disease. The objectives of this study contributed to investigating the molecular and serologic characteristics of β-thalassemia patients in Iraq. Peripheral blood samples were collected from 97 β-thalassemia patients and 32 healthy control subjects. Quantitative sandwich enzyme-linked immunosorbent assay was performed to measure serum ferritin, 25-hydroxy vitamin D, and 8-hydroxydeoxyguanosine (8-OHdG) levels. Further, the β-globin mutation detection assay involving an extensive screening of β-globin mutations by direct Sanger DNA sequencing and gap-PCR was performed to detect the Δ619 deletion mutation. The results revealed that compared with the control subjects, the β-thalassemia patients showed significantly decreased vitamin D levels and significantly increased serum ferritin and 8-OHdG levels (all, P<0.001). Molecular analysis detected 9 types of mutations in the β-thalassemia patients, only 2 of which, namely IVS II-1 G>A and IVS 1-5 G>C, have been previously reported in Iraqi studies, whereas the remaining 7, namely IVS-II-666 C>T, CD2 CAT>CAC, IVS-II-850 G>A, IVS-II-16 G<C, Hb King's Mill, Hb Saveh, and IVS-II-81 C>T, have never been reported in the Iraqi population. This study showed that the serum ferritin and 8-OHdG levels were significantly higher, and the serum 25-hydroxy vitamin D levels were significantly lower in the β-thalassemia patients than in the control subjects. Moreover, the results revealed seven newly identified mutations among Iraqi β-thalassemia patients and 2 previously reported mutations.

Cd60 (GTG > GAG)/Hb Cagliari mutation was found in scanning of β-thalassemia alleles from patients of East Kalimantan, Indonesia

Background and purpose

Thalassemia is a genetic disorder with a fairly high prevalence worldwide. Three to 10% of Indonesian people are estimated to be carriers for thalassemia. This study was intended to figure out the spectrum of genetic mutations of patients with thalassemia in Samarinda City, East Kalimantan.

Methods

The research subjects consisted of 31 β-thalassemia patients registered with the Association of Thalassemia Patients' Parents (POPTI) of Samarinda. DNAs were extracted from the patients' blood samples then amplified by the direct sequencing technique with polymerase chain reaction to analyze β-globin gene mutations.

Result

The study results show that the male/female ratio was 51.6%:48.4%, the patients' ages ranged from 4 years to 56 years with an average age of 14 years, and the dominant ethnic group was Javanese (64.5%). The DNA analysis yielded 7 types of mutant alleles, namely Cd26/HbE (GAG>AAG) at 48.4%, IVS-1-5 (G > C) at 14.5%, IVS-1-2 (T > C) at 12.9%, Cd35 (-C) at 8.1%, IVS-1-1 (G > T) at 6.5%, and, the least frequently encountered mutant alleles, Cd30 (AGG > ACG) and Cd60 (GTG > GAG) each at 3.2%.

Conclusion

This study discovered unreported mutant in Indonesia, namely Cd60 (GTG > GAG).

A Novel εγδβ-Thalassemia Deletion Associated with Severe Anemia at Birth and a β-Thalassemia Intermedia Phenotype Later in Life in Three Generations of a Greek Family

We describe a novel deletion causing heterozygous εγδβ-thalassemia (εγδβ-thal) across three generations of a Greek family. The Greek deletion is about 72 kb in length, spanning from the hypersensitive site 4 (HS4) in the locus control region (LCR) to the 3' end of the β-globin gene, thus encompassing the entire β-globin gene cluster. The deletion caused severe but transient neonatal anemia and a non transfusion-dependent chronic hemolytic anemia state later in life, resembling mild β-thalassemia intermedia (β-TI) rather than β-thalassemia (β-thal) trait, as had been previously reported. Apart from the presentation of clinical and laboratory characteristics, the challenges involving clinical management are also discussed.

Consanguineous unions and endogamy in families of beta-thalassaemia patients from two Mediterranean populations: Tunisia and Italy

Background: Consanguinity increases the incidence of recessive diseases such as beta-thalassaemia major (βTM), one of the most prevalent lethal inherited diseases in the world.Aim: This study aims to identify the frequency of endogamy and consanguinity in two Mediterranean βTM populations and to study the implication of socio-economic factors.Subjects and methods: A trans-sectional study was conducted in 203 Tunisian families and 75 Italian families. Data were collected using a questionnaire completed by patients and parents.Results: Complete endogamy and consanguinity were observed in 82.75% and 62.56% of Tunisian families, respectively. Complete endogamy was found in 90.67% of Italian families, no consanguinity was noted. The low occupation status of Tunisian mothers was associated with an increasing frequency of consanguinity (p = .01) and endogamy (p = .0003). Consanguinity was associated with low education level (p = .012) and low occupation status (p=.047) of fathers. No significant association was found between endogamy and socio-economic factors in the Italian sample.Conclusions: High consanguinity and endogamy rates in Tunisian families may explain the frequency of βTM in Tunisia. The high endogamy rate in Italian families could also increase the frequency of βTM. Identification of geographical distribution and socio-economic factors leading to endogamy and consanguinity in these populations might help to improve βTM prevention.

Study of Frequency and Characteristics of Red Blood Cell Alloimmunization in Thalassemic Patients: Multicenter Study from Palestine

Background. β-Thalassemia is a common inherited hemolytic disorder in Palestine. Red blood cell (RBC) transfusion is the principal treatment but it may cause RBC alloimmunization. This study was conducted to determine the prevalence and characteristics of RBC alloimmunization among thalassemic patients in northern governorates of Palestine. Methods. A prospective multicenter observational study was conducted in the thalassemia transfusion centers in the northern governorates of Palestine. The study included 215 thalassemia patients who received regular blood transfusions. Clinical and transfusion records of patients were examined. Antibody screening and identification was conducted using the microcolum gel technique. Results. Two hundred fifteen patients were included in the study. More than half (52.1%) of the patients were males. The median age of patients was 18 years (range: 12–24 years). The most frequent blood group was A (40.5%). Alloantibodies were detected in 12.6% of patients. Anti-D (33.3%), anti-K (25.9%) and anti-E (14.8%) were the most commonly isolated antibodies. There was no association between age, sex, starting age of transfusion, number of transfused units, history of splenectomy and alloimmunization. Conclusions. Anti-Rh and anti-K antibodies were common among this cohort of patients. Age, sex, starting age of transfusion, number of transfused units, and history of splenectomy could not predict the occurrence of alloimmunization.

Disease Knowledge and Treatment Adherence among Adult Patients with Thalassemia: A Cross-sectional Correlational Study

Aim. To investigate the disease knowledge and treatment adherence among adult patients with thalassemia.

Material and methods. A cross-sectional correlational study was carried out with a convenience sample of 100 adult patients with thalassemia from a university teaching hospital in Jeddah city, Saudi Arabia. The Disease Knowledge about Thalassemia Major, the Treatment Adherence Scale, and sociodemographic survey were completed by participants. The data were analyzed using Statistical Package for the Social Sciences version 22. Descriptive and inferential statistics and Pearson correlations were performed.

Results. The participants had a moderate level of disease knowledge (M = 15.59, SD = 2.30) and a low level of treatment adherence (M = 3.91, SD = 1.83). There was also a weak but significant positive relationship between disease knowledge and treatment adherence (r = 0.297, P = 0.041). A significant difference in treatment adherence mean scores was found among participants with different monthly incomes (P = 0.05).

Conclusions. Knowledge gained from this study may be useful in improving nurses’ understanding of the effects of providing practical knowledge on treatment adherence. Educational strategies/interventions programs may be required to improve knowledge and adherence to treatment among thalassemia patients. Longitudinal studies are also needed to test for moderators and mediators of relationships of disease knowledge and treatment adherence.

A β-Thalassemia Trait with Two Mutations in Cis in a Chinese Family

A female of Chinese origin carried the codon 43 (G>T) (HBB: c.130G > T) and codons 71/72 (+A) (HBB: c.216_217insA) mutations of the β-globin gene in cis, identified during prenatal thalassemia screening. The double in cis mutations were inherited from her mother. Both of the two carriers behave as a traditional heterozygote for β-thalassemia (β-thal) with microcytosis and a high Hb A₂ level. This case report indicates that the possibility of multiple mutations in cis in a fetus with thalassemia trait has to be considered in a prenatal screening program.

TGA/Chemometric Test Is Able to Detect the Presence of a Rare Hemoglobin Variant Hb Bibba

In this study the TGA/Chemometric test was applied for diagnosis of a case of congenital hemolytic anemia for which the common first level diagnostic tests were not able to find the erythrocyte congenital defect. A 6 years old girl presented chronic hemolytic anemia characterized by hyperbilirubinemia, increased spleen, negative Coombs tests, normal hemoglobin values, decreased mean corpuscular volume (MCV), increased red cell distribution width (RDW), reticulocytes and lactate dehydrogenase (LDH), and altered erythrocyte morphology (ovalocytes, spherocytes, and rare schizocytes). The diagnostic protocols for differential diagnosis of hereditary hemolytic anemia were carried out by the investigation of the congenital hemolytic anemias due to defects of membrane proteins and the most common erythrocyte enzymes, but no defect was found. The TGA/Chemometric test was applied and the PLS-DA model of prediction was used to process results. The thermogravimetric profile of the patient was very distinct from those of healthy subjects and comparable with those of thalassemia patients. The classification model applied to the patient identified a chronic hemolytic anemia due to a hemoglobin defect and the molecular characterization confirmed the TGA/Chemometrics results, demonstrating the presence of a very rare hemoglobin variant Hb Bibba (α₂136(H19)Leu → Proβ₂). In conclusion the TGA/Chemometric test proved to be a promising tool for the screening of the hemoglobin defects, in a short time and at low cost, of this case of congenital hemolytic anemia of difficult diagnosis. This method results particularly suitable in pediatric patients as it requires small sample volumes and is able to characterize patients subjected to transfusion.

Ocular abnormalities in beta thalassemia patients: prevalence, impact, and management strategies

BACKGROUND

Beta thalassemia (β-thalassemia) is a hereditary disease caused by defective globin synthesis and can be classified into three categories of minor (β-TMi), intermedia (β-TI), and major (β-TM) thalassemia. The aim of our study is to investigate the effects of β-thalassemia and its treatment methods on different parts of the eye and how early-diagnostic methods of ocular complications in this disorder would prevent further ocular complications in these patients by immediate treatment and diet change.

METHODS

We developed a search strategy using a combination of the words Beta thalassemia, Ocular abnormalities, Iron overload, chelation therapy to identify all articles from PubMed, Web of Science, Scopus, and Google Scholar up to December 2018. To find more articles and to ensure that databases were thoroughly searched, the reference lists of selected articles were also reviewed.

RESULTS

Complications such as retinopathy, crystalline lens opacification, color vision deficiency, nyctalopia, depressed visual field, reduced visual acuity, reduced contrast sensitivity, amplitude reduction in a-wave and b-wave in Electroretinography (ERG), and decrease in the Arden ratio in Electrooculography (EOG) have all been reported in β-thalassemia patients undergoing chelation therapy.

CONCLUSION

Ocular problems due to β-thalassemia may be a result of anemia, iron overload in the body tissue, side effects of iron chelators, and the complications of orbital bone marrow expansion.