Coinheritance of HbO Arab/β0-thalassemia with Severe Manifestation in Newborn

OBJECTIVE

 In this study, we report a Tunisian newborn boy referred for neonatal hemolytic anemia with yellowish skin and enlarged spleen due to coinheritance of hemoglobin O (HbO) Arab and β-thalassemia.

STUDY DESIGN

 Hematological parameters were collected using an automated blood cell counter. The amounts of Hb fractions were measured by capillary electrophoresis of Hb. Amplification and sequencing of the HBB gene were performed by Sanger's method.

RESULTS

 Family study and genetic analysis revealed that the proband was a carrier of two hemoglobinopathies: HbO Arab and β0-thalassemia.

CONCLUSION

 The coexistence of these two pathologies complicated the general state of the newborn boy and led to a severe anemia at birth.

KEY POINTS

· Severe neonatal anemia can be caused by hemoglobinopathy.. · Coinheritance of HbO Arab/β0-thalassemia complicated the general state of the newborn.. · Diagnosing hemoglobinopathy at an early age improves patient care..

TP53 Gene 72 Arg/Pro (rs1042522) single nucleotide polymorphism increases the risk and the severity of chronic lymphocytic leukemia

Background

Genetic variations in TP53 gene are known to be important in chronic lymphocytic leukemia (CLL) and may cause its inactivation which is associated with an aggressive form of the disease. Single nucleotide polymorphism (rs1042522:G>C) in TP53 gene at codon 72 encodes for arginine (Arg) or proline (Pro) variant which results in amino acid substitution affecting the apoptotic potential of TP53 protein. The aim of this study was to assess the correlation between TP53 codon 72 polymorphism and risk susceptibility as well as severity of CLL among Tunisian patients.

Materials and methods

A case-control study was conducted in Tunisia from February 2019 to November 2021, 160 de novo CLL patients and 160 healthy volunteers matched in age and gender were involved. DNA was extracted from peripheral blood mononuclear cells and the rs1042522 was analyzed using PCR-RFLP.

Results

Pro variant was associated with higher susceptibility to CLL than Arg variant (p= 0.023). A significant association was found between Pro variant and prognostic classification of Binet stage C (p= 0.001), low hemoglobin level (p= 0.003) and low platelet count (p= 0.016).

Conclusion

We suggest that Pro variant may increase the risk of developing CLL in our population and could be associated with the severity of the disease.

PHINDaccess Hackathons for COVID-19 and Host-Pathogen Interaction: Lessons Learned and Recommendations for Low- and Middle-Income Countries

Hackathons are collaborative events that bring together diverse groups to solve predefined challenges. The COVID-19 pandemic caused by SARS-CoV-2 has emphasized the need for portable and reproducible genomics analysis pipelines to study the genetic susceptibility of the human host and investigate human-SARS-CoV-2 protein interactions. To build and strengthen institutional capacities in OMICS data analysis applied to host-pathogen interaction (HPI), the PHINDaccess project organized two hackathons in 2020 and 2021. These hackathons are aimed at developing bioinformatics pipelines related to the SARS-CoV-2 viral genome, its phylodynamic transmission, and the identification of human genome host variants, with a focus on addressing global health challenges, particularly in low- and middle-income countries (LMIC). This paper outlines the preparation, proceedings, and lessons learned from these hackathons, including the challenges faced by participants and our recommendations based on our experience for organizing hackathons in LMIC and beyond.

Molecular characterization of a novel homozygous deletion in β-globin cluster causing (δβ)0-Thalassemia among Tunisian family

BACKGROUND

Deletions in the β-globin cluster are uncommon and cause thalassemia (thal) with hereditary persistence of fetal hemoglobin. They constitute a heterogenous group of disorders characterized by absent or reduced synthesis of adult hemoglobin (Hb A) and increased synthesis of fetal hemoglobin (Hb F). Although the clinical severity of these disorders are asymptomatic owing to the increased Hb F levels, the molecular basis is very heterogenous due to the large deletions in the β-globin cluster spanning both HBD and HBB genes. Here, we describe a Tunisian family carrying a novel deletion mutation causing (δβ)°-thalassemia.

METHODS

The amounts of hemoglobin fractions were measured by capillary electrophoresis of hemoglobin. Amplification and sequencing of different regions on the β-gene cluster were performed by Sanger method.

RESULTS

Family study and genetic analysis revealed a large deletion mutation in the β-globin cluster of 14.5 kb (NG_000,007.3:g. 58,253 to g.72837del14584) at the homozygous state in the patient and at heterozygous state at the other members of the family. This deletion removes the HBD and HBB genes.

CONCLUSIONS

In our knowledge, this new large deletion is described for the first time in the Tunisian population and in the world, designed Tunisian(δβ)⁰ in Ithanet database (IthaID: 3971). Therefore, it is important to identify the deletion leading to δβ-thalassemia carriers at the molecular level, to highlight the importance of recognizing the clinical features and implementing appropriate testing to clarify the diagnosis and manage the condition.

Emotional and behavioral attitudes of Tunisian youth towards childhood leukemia: health education and primary prevention in perspective

Background

Given the increasing blood cancer incidence in Tunisia and recent discoveries proving the involvement of environmental factors, this study examined the environmental health literacy (EHL) of Tunisian secondary school students concerning not only this disease, but also their emotional and behavioral attitudes towards leukemia risks.

Methods

A cross-sectional survey was conducted among Tunisian youths (N = 372, 16–20 years; 68% females, 32% males). Data collection took place in four representative public secondary schools in the North, Center, and South of Tunisia. Students completed a paper and pencil questionnaire and described their EHL level of blood cancer, as well as their attitudes and interests in this disease. The statistical software (SPSS, v.25.0) was used to analyze the data collected.

Results

The results indicated low EHL levels of leukemia. Most youths failed to identify all the leukemogenic (except tobacco and pollution) and non- leukemogenic risk factors. Pesticide use and exposure to low frequency electromagnetic radiation were not considered risk factors. Proximity to heavy-traffic roads and benzene exposure were not perceived by youth as risk factors. Despite these low levels, most participants were interested in having more information about leukemia and cancers in general.

Conclusion

This investigation shows a lack of knowledge about leukemia. Low EHL levels will incite educational actors and curriculum designers to optimize content and innovate ICT adapted to this environmental health challenge.

Eryptosis and circulating blood cells microparticules in sickle cell diseases

Sickle cell disease(SCD)is a monogenic disease, in which the severity and symptoms vary widely.The sickle cell mutation is the origin of all functional and structural alterations of red blood cell(RBC)which induces the acceleration of eryptosis and formation of Circulating blood cells microparticules(MPs)which has the consequence of acute anemia and increasing the thrombotic risks in sickle cell patients. Eryptosis is the suicidal erythrocyte death characterized by erythrocyte membrane scrambling by phosphatidylserine(PS)externalization. MPs are an extracellular vesicules released following cellular activation, stress or apoptosis. These parameters are able to modulate many biological functions, and considered as biomarkers of preventive diagnostic of SCD. This present study aims to determine the cellular biomarkers to implementation new and innovative methods of the preventive diagnosis of SCDacute complications. We propose to study the mechanisms involved in the triggering of eryptosis and to quantify microparticles derived from platelets and erythrocytes of homozygous sickle cell patients.

Following clinical diagnosis, homozygous SCDpatients and healthy donors were sampled for hematological and cellular assays. The exploration of eryptosis and MPs was performed by a flow cytometry by determining the viability parameters of red blood cells.

The outcome of our study indicated that Eryptosis in sickle cell patients is triggered essentially by high Ca2 + entry and narrowing of red blood cells. However, the pathway of ceramides and ERO can also considered a stimulating factor of eryptosis. Eryptosis ensures healthy erythrocyte quantity in circulation whereas excessive eryptosis is the cause of acute anemia and may contribute to vaso-occlusive crisis in SCD patients.For MPs study,microparticles derived from platelets and erythrocytes clearly increased in SCD patients. This suggests that erythrocytes MPs may contribute to thrombotic risk andchronic hemolytic anemia.

Key messages

Potentiel biomarkers in the preventive diagnosis of sickle cell disease. Eryptosis and plasmatic microparticules as potentiel biomarkers.

Empowering Tunisians Youth to seasonal influenza: Auto medication versus empathy

Background and aim

In Tunisia, self-medication against seasonal influenza is a public health problem that mainly affects low- and middle-income social categories. For implementation of an educational intervention, this study will assess young Tunisians' literacy towards Seasonal Influenza. Health education, socio-demographic (gender and intersectionality) and media variables will be explored.

Methods

This is a cross-sectional study, which included Tunisian students from different educational levels and residents in different regions of the country.

Results

The results show that the risk perception and level literacy depend on gender, geographical proximity, media coverage and didactic choices. The fears of male students in preparatory or secondary school focus significantly more than for female school students around seasonal Influenza, respectively (21.5% vs. 10%, p < 0.05) and (25.7% vs 7.4%, p < 0.05). Among the behaviors purposed to students, to protect themselves from infectious diseases, the consumption of antibiotics! ranks second before personal hygiene (hand washing), vaccination and avoidance measures. In general, 'avoid public places' and 'avoid taking public transport' are behaviors that seem little or not adopted in case of influenza whatever the school level or the study specialty of youths. Questions were asked, moreover, on 'the acceptability of the mask wearing in family and in the public space'. Only 14% preparatory school students and 11% of secondary school students would 'totally' agree to wear it at home and away from home.

Conclusions

Considering the literacy level of young Tunisians towards the seasonal influenza, pandemic and MDR risks remains high. Innovative educational interventions, which combining epidemiological and ecological knowledge (social, economic, scientific, epidemiological and individual contexts), would be better adapted to new and emerging health issues and could reduce social inequalities in health.

Key messages

Social qualification in the face of infectious diseases. Development of capacities to perceive and manage seasonal Influenza.

The role of rs1984112_G at CD36 gene in increasing reticulocyte level among sickle cell disease patients

AIMS AND BACKGROUND

Mediators of adhesion become a potential new target for pharmacological therapy to struggle the complications of sickle cell disease (SCD). Several mechanisms for increased adherence have been postulated and the well-studied are CD36 and VLA4 which encoded by ITGA4. Herein, we sought to determine whether one polymorphism of CD36 namely: rs1984112 and three exons of ITGA4 (4, 5, and 6) are implicated in hemolytic status and clinical events among SCD Tunisian patients.

MATERIAL AND METHODS

This study enrolled 99 unrelated Tunisian subjects (63SS and 36Sβ). All SCD patients are children (less than 16 years old). The rs1984112 and the ITGA4's exons 4, 5, and 6 were analyzed for all subjects by PCR/sequencing. The association of each genotype found with both clinical complications and hemolytic status was performed using t-test. Clinical events studied included vaso-occlusive crisis (VOC), osteonecrosis, stroke, frequent infection, priapism, and acute syndrome.

RESULTS

The results show that rs1984112_G allele at CD36 gene revealed to be associated with higher levels of reticulocyte count (p < 0.01). The statistical result show a near significance of homozygous mutant GG genotype with VOC (p = 0.051). No association between rs1984112_G allele and the clinical severity of SCD were found. Mutational screening of exon 4, 5, and 6 of ITGA4 gene revealed absence of mutated variant.

CONCLUSION

Our results are similar to those found in Portuguese population which reported the role of rs1984112_G in increasing reticulocyte level among SCD patients. Consequently, the rs1984112_G of CD36 could be considered as a reliable biomarker for predicting patients at high risk for vascular occlusions and thus, allows earlier and more effective therapeutic management.

rs11886868 and rs4671393 of BCL11A associated with HbF level variation and modulate clinical events among sickle cell anemia patients

AIMS

Fetal hemoglobin (HbF) modulates the phenotype of sickle cell anemia (SCA) by inhibiting deoxy sickle hemoglobin (HbS) polymerization. HbF genes are genetically regulated, and the level of HbF and its distribution among sickle erythrocytes is highly variable. Herein, we aimed to determine whether two functional polymorphisms of BCL11A are implicated in the variation of HbF and clinical events in SCA Tunisian patients.

MATERIAL AND METHODS

The studied population consisted of 148 SCA patients with SS phenotype. The group of patients was divided into two subgroups according to the threshold point of %HbF which is 15%. Genotyping of rs11886868 and rs4671393 was performed using PCR/Sequencing. To test for trait association with the candidate SNPs, genotype and allele frequencies between 'group who had %HbF < 15' and 'group who had %HbF >15' (controls) were compared using Pearson's chi-square test (compare 2, version 1.02). The association of each genotype and the combined genotype with complications was performed by logistic regression test.

RESULTS

Our findings showed that the majority of patients carried genotype CT of rs11886868 and genotypes AG and GG of rs4671393 present HbF level < 15%. RR = 0.08, RR = 0.176, and RR = 0.189, respectively. The results showed a significant association between the alleles T of rs11886868 and G of rs4671393 and %HbF < 15% with P = 0.016; RR = 0.39 and P = 8.9 × 10-3: RR = 0.567, respectively. Interestingly, the C allele of the rs11886868 and the A allele of the rs46713939 were associated with an ameliorated phenotype in patient's SCA. The combination of the genotypes GG and CT explains more phenotypic variance than the sum of the two BCL11A SNPs taken individually.

rs11886868 and rs4671393 of BCL11A associated with HbF level variation and modulate clinical events among sickle cell anemia patients

AIMS

Fetal hemoglobin (HbF) modulates the phenotype of sickle cell anemia (SCA) by inhibiting deoxy sickle hemoglobin (HbS) polymerization. HbF genes are genetically regulated, and the level of HbF and its distribution among sickle erythrocytes is highly variable. Herein, we aimed to determine whether two functional polymorphisms of BCL11A are implicated in the variation of HbF and clinical events in SCA Tunisian patients.

MATERIAL AND METHODS

The studied population consisted of 148 SCA patients with SS phenotype. The group of patients was divided into two subgroups according to the threshold point of %HbF which is 15%. Genotyping of rs11886868 and rs4671393 was performed using PCR/Sequencing. To test for trait association with the candidate SNPs, genotype and allele frequencies between 'group who had %HbF < 15' and 'group who had %HbF >15' (controls) were compared using Pearson's chi-square test (compare 2, version 1.02). The association of each genotype and the combined genotype with complications was performed by logistic regression test.

RESULTS

Our findings showed that the majority of patients carried genotype CT of rs11886868 and genotypes AG and GG of rs4671393 present HbF level < 15%. RR = 0.08, RR = 0.176, and RR = 0.189, respectively. The results showed a significant association between the alleles T of rs11886868 and G of rs4671393 and %HbF < 15% with P = 0.016; RR = 0.39 and P = 8.9 × 10(-3): RR = 0.567, respectively. Interestingly, the C allele of the rs11886868 and the A allele of the rs46713939 were associated with an ameliorated phenotype in patient's SCA. The combination of the genotypes GG and CT explains more phenotypic variance than the sum of the two BCL11A SNPs taken individually.

Two new β+ -thalassemia mutation [β -56 (G → C); HBBc. -106 G → C] and [β -83 (G → A); HBBc. -133 G → A] described among the Tunisian population

OBJECTIVES

Different thalassemia mutations have been reported in various ethnic groups and geographical regions in Tunisia. In the present study, we have investigated two rare β(+) -thalassemia mutations, that have not previously been reported in the Tunisian population [β -56 (G > C); HBBc. -106 G > C] and [β -83 (G > A); HBBc. -133 G > A].

METHODS

The whole β-globin gene was directly sequenced, and haplotype analysis was conducted through a PCR/RFLP method.

RESULTS

Two new mutations were identified for the first time in Tunisia. They are located within the promoter region of β-globin gene at position -56 (G > C) and -83 (G > A). Linkage analysis using β-globin gene cluster haplotypes showed that these two mutations were associated with Mediterranean β-haplotype IX [- + - + + + +] and framework 2 (FW2) [CCTCT].

CONCLUSIONS

The two newly described mutations lead to the β(+) -thalassemia among Tunisian patients. The haplotype analysis and framework assignment have helped to identify the chromosomal background associated with these mutations, and determine their origin and spread.

Fetal Hemoglobin in Tunisian Sickle Cell Disease Patient: Relationship with Polymorphic Sequences Cis to the β-Globin Gene

Fetal hemoglobin (HbF) plays a dominant role in ameliorating morbidity and mortality of hemoglobinopathies. We evaluated the effects of polymorphic markers within the β-globin gene cluster to identify the genetic mechanics that influence HbF on Tunisian sickling patients (n = 242). Haplotype analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the framework polymorphism was established by PCR-sequencing, four independent regions of interest were identified: the 5' region of β-LCR-HS2 site, the intervening sequence II (IVSII) region of two fetal (Gγ and Aγ) genes and the 5' region of β-globin gene. The correlation of these various Haplotypes and SNPs with HbF expression and clinical data was studied. Our data showed that among the various polymorphic markers analyzed, only the sequence (AT)xN12(AT)y in LCR HS2 region was significantly associated (p < 0.05) with increased HbF levels, suggesting that the β-globin gene cluster exerts a significant effect on HbF in sickle cell patients. This study can improve understanding of the physiopathology of the disease and aid to increase our ability to predict clinical severity.

Association of lymphotoxin alpha polymorphism with type 1 diabetes in a Tunisian population

We investigated the association of the lymphotoxin (LT)-α gene polymorphism +249A/G with type 1 diabetes. The distribution of genotypes of the LT-α +249A/G single nucleotide polymorphism (SNP) was assessed in 115 diabetic patients and 123 normoglycemic control subjects, using PCR-restriction fragment length polymorphism analysis. Among unselected patients, the SNP was significantly associated with increased risk of diabetes (χ2 = 8.44, p = 0.014) and was found to be more pronounced among female (χ2 = 8.37, p = 0.02) than male (χ2 = 6.11, p = 0.047) patients. A significant association was detected between LT-α +249A/G and increased risk of diabetes, in particular for young-onset patients (χ2 = 6.92, p = 0.031). Moreover, we reported significant differences in levels of HbA1c, triglycerides, alanine transaminase, and anti-glutamic acid decarboxylase-65 among alleles. Additional studies with extended patient age groups and different ethnicities are needed to confirm our findings.

Early complication in Sickle Cell Anemia children due to A(TA)<formula>_n</formula> TAA polymorphism at the promoter of UGT1A1 gene

AIM: To determine the implication of the polymorphism namely A(TA)nTAA of UGT1A1 in lithogenesis for the first time in Tunisia among sickle cell anemia (SCA) children patients. MATERIAL AND METHODS: Our study was performed in 2010 and it involved 76 subjects chosen as control group characterized with normal hemoglobin status and presence of cholelithiasis and 102 SCA pediatric patients among whom 52 have cholelithiasis. We analyzed the polymorphism A(TA)_{n} TAA at the UGT1A1 promoter and the relationships between the various A(TA)_{n} TAA genotypes and alleles and bilirubin levels and occurrence of cholelithiasis. RESULTS AND DISCUSSION: The repartition of genotypes found according to serum bilirubin level shows a significant association between genotypes carried variant (TA)_{7} and hyperbilirubinemia (p< 0.05). We demonstrated the association of two genotypes with gallstones formation among SCA children patients: (TA)_{7}/(TA)_{7} and (TA)_{7}/(TA)_{8} with p=8.1 × 10^{ - 8} and p=0.01 respectively. (TA)_{7} and (TA)_{8} allele variants act as a risk factor for early gallstones formation in SCA patients with p=5.8 × 10^{ -9} and p=0.01 respectively. As for the control group only the genotype (TA)_{7}/(TA)_{7} presented a risk factor for gallstones formation. CONCLUSION: The novelty of this report is that it is the first time that a similar study was made on the Tunisian children sickle cell population and that the results show a clear association of (TA)_{7} variant in early gallstones formation in Tunisian SCA children. Interestingly our findings highlighted the association of (TA)_{8} variant as well, which was not found in previous studies.

Two new class III G6PD variants [G6PD Tunis (c.920A>C: p.307Gln>Pro) and G6PD Nefza (c.968T>C: p.323 Leu>Pro)] and overview of the spectrum of mutations in Tunisia

We screened 423 patients referred to our laboratory after hemolysis triggered by fava beans ingestion, neonatal jaundice or drug hemolysis. Others were asymptomatic but belonged to a family with a history of G6PD deficiency. The determination of enzymatic activity using spectrophotometric method, revealed 293 deficient (143 males and 150 females). The molecular analysis was performed by a combination of PCR-RFLP and DNA sequencing to characterize the mutations causing G6PD deficiency. 14 different genotypes have been identified : G6PD A(-) (376A>G;202G>A) (46.07%) and G6PD Med (33.10%) were the most common variants followed by G6PD Santamaria (5.80%), G6PD Kaiping (3.75%), the association [c.1311T and IVS11 93c] (3.75%), G6PD Chatham (2.04%), G6PD Aures (1.70%), G6PD A(-) Betica (0.68%), the association [ 376G;c.1311T;IVS11 93c] (0.68%), G6PD Malaga, G6PD Canton and G6PD Abeno respectively (0.34%). Two novel missense mutations were identified (c.920A>C: p.307Gln>Pro and c.968T>C: p.323 Leu>Pro). We designated these two class III variants as G6PD Tunis and G6PD Nefza. A mechanism which could account for the defective activity is discussed.

A silent composite hemoglobinopathy characterized by gene sequencing

We report the case of a 35-year-old Tunisian women with a chronic anemia non investigated for a long time. Laboratory analysis using advanced technology of DNA sequencing revealed a compound heterozygote for Hb O Arab and cd 39 beta degrees-thalassemia. It's the first time that such a genotype has been characterized by gene sequencing.

Hb A2-Pasteur-Tunis [δ59(E3)Lys→Asn, AAG→AAC]: A New δ Chain Variant Detected by DNA Sequencing in a Tunisian Carrier of the Codon 39 (C→T) β0-Thalassemia Mutation

We describe a new delta-globin variant, Hb A2-Pasteur-Tunis [delta59(E3)Lys-->Asn, AAG-->AAC]. This hemoglobin (Hb) displayed an electrophoretic mobility faster than normal Hb A2 and was expressed at 2.2 %. The molecular defect was characterized by DNA sequencing and confirmed by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-designed protocol. Hb A2-Pasteur-Tunis was found in a carrier of a codon 39 (C-->T) beta0-thalassemia (thal), presenting with a normal Hb A2 level. Phenotype and genotype investigations revealed that the total Hb A2 level of the patient was that expected for a minor beta-thal (4.8%).