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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 β 0 -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/β 0 -thalassemia complicated the general state of the newborn. Diagnosing hemoglobinopathy at an early age improves patient care. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 byITGA4. Herein, we sought to determine whether one polymorphism ofCD36namely: rs1984112 and three exons ofITGA4(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 theITGA4’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 usingt-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 atCD36gene 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 ofITGA4gene 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 ofCD36could be considered as a reliable biomarker for predicting patients at high risk for vascular occlusions and thus, allows earlier and more effective therapeutic management. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. Am. J. Hum. Biol. 27:716-719, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

ß-Globin haplotypes are important to establish the ethnic origin and predict the clinical development of sickle cell disease patients (SCD). To determine the chromosomal background of ßs Tunisian sickle cell patients, in this first study in Tunisia, we have explored four polymorphic regions of ß-globin cluster on chromosome 11. It is the 5' region of ß-LCR-HS2 site, the intervening sequence II (IVSII) region of two fetal (Gγ and Aγ) genes and the 5' region of ß-globin gene. The results reveal a high molecular diversity of a microsatellite configuration describing the sequences haplotypes. The linkage disequilibrium analysis showed various haplotype combinations giving 22 "extended haplotypes". These results confirm the utility of the ß-globin haplotypes for population studies and contribute to knowledge of the Tunisian gene pool, as well as establishing the role of genetic markers in physiopathology of SCD. [ABSTRACT FROM AUTHOR]

Aim. To determine the implication of the polymorphism, namely, A(TA)n TAA 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)nTAA at the UGT1A1 promoter and the relationships between the various A(TA)nTAA 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 carrying 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 wasmade 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. [ABSTRACT FROM AUTHOR]

The diversity of sickle cell disease severity is attributed to several cis acting factors, among them the single nucleotide polymorphisms (SNPs) and (AT) rich region in the β-locus control region (β-LCR). This contains five DNase I hypersensitive sites (HS) located 6 to 22 kb upstream to the ε gene. The most important of these is the HS2 (5′ β-LCR-HS2), characterized by the presence of three different SNPs and a microsatellite region known to be in association with βS chromosomes in various populations. The aim of this study was to present the molecular investigation of the 5′ β-LCR-HS2 site in normal and sickle cell disease individuals in order to determine if there is any correlation or specificity between these molecular markers, the βS Tunisian chromosomes and phenotypical expression of sickle cell disease. One hundred and twenty-four chromosomes from Tunisian individuals (49 βS carriers and 13 normal individuals) were screened by polymerase chain reaction (PCR) and sequencing for the polymorphic short tandem microsatellite repeats (AT)XN12(AT)Y and the three SNPs (rs7119428, rs9736333 and rs60240093) of the 5′ β-LCR-HS2. Twelve configurations of the microsatellite motif were found with an ancestral configuration elaborated by ClustalW software. Normal and mutated alleles were observed at the homozygous and heterozygous states for the three SNPs. Correlation between microsatellites and SNPs suggests that mutant SNP alleles were mainly associated, in the homozygous sickle cell disease phenotype, with the (AT)8N12GT(AT)7 configuration, whereas, normal SNP alleles were associated with the (AT)XN12(AT)11 configurations in normal βA chromosomes. The correlation of these various configurations with Hb F expression was also investigated. The principal component analysis (PCA) showed the correlation between the homozygous sickle cell disease phenotype, mutated SNP alleles and the Benin microsatellite configuration (AT)8N12GT(AT)7, which confirmed the specificity of this configuration to the βS chromosomes. In addition, the observed high level of Hb F (14.6%) could play a protective role against Hb S to justify the modulation of sickle cell disease severity within the Benin haplotype compared to the other haplotypes. This study highlights the fact that the β-LCR-HS2 could be a genetic marker to identify the ethnic Tunisian βS chromosomes and facilitate the molecular diagnosis of sickle cell disease. [ABSTRACT FROM AUTHOR]

We describe a new δ-globin variant, Hb A2-Pasteur-Tunis [δ59(E3)Ly(s)→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) β0-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 β-thal (4.8%). [ABSTRACT FROM AUTHOR]

We describe a new δ-globin variant, Hb A2-Tunis [δ46(CD5)Gly → Glu; HBD: c.140G>A]. This hemoglobin (Hb) variant displayed a faster electrophoretic mobility than normal Hb A2 and was expressed at 3.2%. The molecular defect was characterized by DNA sequencing analysis. Hb A2-Tunis was found in a carrier of a β0-thalassemia (β0-thal) [IVS I-1 (β143, G>A); HBB: c.92 + 1G>A] and Hb C [β6(A3)Glu → Lys; HBB: c.19G>A], presenting with a normal Hb A2 level. Phenotype and genotype investigations revealed that the patient has a total Hb A2 level of 7.1% that was expected for a β-thalassemia (β-thal) minor carrier. [ABSTRACT FROM AUTHOR]