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1.
BMC Med Ethics ; 22(1): 49, 2021 04 29.
Article in English | MEDLINE | ID: mdl-33926431

ABSTRACT

BACKGROUND: We describe our experience from a multi-national application of a European Union-funded research-driven paediatric trial (DEEP-2, EudraCT 2012-000353-31; NCT01825512). This paper aims to evaluate the impact of the local and national rules on the trial authorisation process in European and non-European countries. National/local provisions and procedures, number of Ethics Committees and Competent Authorities to be addressed, documentation required, special provisions for the paediatric population, timelines for completing the authorisation process and queries received were collected; compliance with the European provisions were evaluated. Descriptive analysis, Wilcoxon Rank-Sum test and General Linear Model analysis were used to determine factors potentially influencing the timelines. The Cluster Analysis procedure was used to identify homogenous groups of cases. RESULT: The authorisation process was completed in 7.7 to 53.8 months in European countries and in 17.1 to 27.1 months in non-European countries. The main factors influencing these timelines were the requests for changes/clarifications in European countries and the different national legislations in non-European countries. CONCLUSION: This work confirms that the procedures and requirements for the clinical trial application of a paediatric trial are different. In the European Union, the timeframes for submission were generally harmonised but longer. In non-European countries, delays were caused by national dispositions but the entire authorisation process resulted faster with less requests from ECs/CAs. The upcoming application of Regulation (EU) 536/2014 is expected to harmonise practices in Europe and possibly outside. Networks on paediatric research acting at international level will be crucial in this effort.


Subject(s)
Morals , Research Personnel , Child , Europe , European Union , Humans
2.
J Clin Lab Anal ; 30(5): 392-8, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27086580

ABSTRACT

BACKGROUNDS: ß-Thalassemia is one of the most prevalent worldwide autosomal recessive disorders. It presents a great molecular heterogeneity resulting from more than 200 causative mutations in the ß-globin gene. In Tunisia, ß-thalassemia represents the most prevalent monogenic hemoglobin disorder with 2.21% of carriers. Efficient and reliable mutation-screening methods are essential in order to establish appropriate prevention programs for at risk couples. The aim of the present study is to develop an efficient method based on the denaturing high-performance liquid chromatography (DHPLC) in which the whole ß-globin gene (HBB) is screened for mutations covering about 90% of the spectrum. METHODS: We have performed the validation of a DHPLC assay for direct genotyping of 11 known ß-thalassemia mutations in the Tunisian population. RESULTS: DHPLC assay was established based on the analysis of 62 archival ß-thalassemia samples previously genotyped then validated with full concordance on 50 tests with blind randomized samples previously genotyped with DNA sequencing and with 96% of consistency on 40 samples as a prospective study. CONCLUSION: Compared to other genotyping techniques, the DHPLC method can meet the requirements of direct genotyping of known ß-thalassemia mutations in Tunisia and to be applied as a powerful tool for the genetic screening of prenatal and postnatal individuals.


Subject(s)
Chromatography, High Pressure Liquid/methods , Genetic Testing/methods , Mutation/genetics , beta-Globins/genetics , beta-Thalassemia/diagnosis , DNA Mutational Analysis , Female , Genotype , Humans , Male , Tunisia/epidemiology , beta-Thalassemia/genetics
3.
Clin Chem Lab Med ; 51(11): 2115-24, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23800659

ABSTRACT

BACKGROUND: In Tunisia, thalassemia and sickle cell disease represent the most prevalent monogenic hemoglobin disorders with 2.21% and 1.89% of carriers, respectively. This study aims to evaluate the diagnosis reliability of a series of red blood cell indices and parameters in differentiation of beta-thalassemia trait (ß-TT) from iron deficiency anemia (IDA) and between homozygous sickle cell disease (SS) and sickle cell-thalassemia (ST). METHODS: The study covered 384 patients divided into three groups. The first one is composed of 145 control group, the second consists of 57 ß-TT and 52 IDA subjects and the last one with 88 SS and 42 ST patients. We calculated sensitivity, specificity, positive-predictive values, negative-predictive values, percentage of correctly identified patients and Youden's index for each indice. We also established new cut-off values by receiver operating characteristic curves for each indice. An evaluation study was performed on another population composed of 106 ß-TT, 125 IDA, 31 SS and 17 ST patients. RESULTS: Srivastava Index, mean corpuscular hemoglobin, red blood cell, Mentzer Index (MI) and mean corpuscular hemoglobin concentration show the highest reliability in discriminating ß-TT from IDA with new cut-offs slightly different from those described in literature. Ehsani Index, mean corpuscular volume, MI, Shine and Lal Index and Sirdah Index are the most powerful in the differentiation between SS and ST. CONCLUSIONS: The effectiveness and the simplicity of calculation of these indices make them acceptable and easy to use for differential diagnosis.


Subject(s)
Anemia, Iron-Deficiency/blood , Anemia, Iron-Deficiency/diagnosis , Anemia, Sickle Cell/blood , Anemia, Sickle Cell/diagnosis , Erythrocyte Indices , beta-Thalassemia/blood , beta-Thalassemia/diagnosis , Adolescent , Adult , Diagnosis, Differential , Female , Humans , Male , Predictive Value of Tests , ROC Curve , Young Adult
4.
Clin Chem Lab Med ; 51(8): 1595-603, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23492565

ABSTRACT

BACKGROUND: In Tunisia, thalassemia and sickle cell disease (SS) represent the most prevalent monogenic hemoglobin disorders with 2.21% and 1.89% of carriers, respectively. This study aims to evaluate the diagnosis reliability of 12 red blood cell (RBC) indices in differentiation of ß-thalassemia trait (ß-TT) from iron deficiency anemia (IDA) and between homozygous SS and sickle cell thalassemia (ST). METHODS: The study covered 384 patients divided into three groups. The first one is composed of 145 control group, the second consists of 57 ß-TT and 52 IDA subjects and the last one with 88 SS and 42 ST patients. We calculated sensitivity, specificity, positive-predictive values, negative-predictive values, percentage of correctly identified patients and Youden's Index (YI) for each indice. We also established new cut-off values by receiver operating characteristic curves for each indice. An evaluation study was performed on another population composed of 106 ß-TT, 125 IDA, 31 SS, and 17 ST patients. RESULTS: Srivastava Index (SI) shows the highest reliability in discriminating ß-TT from IDA at 5.17 as a cut-off and also SS from ST with 7.7 as another threshold. Mentzer Index (MI) and RBC appear also useful in both groups with new cut-offs slightly different from those described in literature for ß-TT and IDA. CONCLUSIONS: The effectiveness and the simplicity of calculation of these indices make them acceptable and easy to use. They can be relied on for differential diagnosis and even for diagnosis of ß-TT with atypical HbA2 levels.


Subject(s)
Anemia, Iron-Deficiency/blood , Anemia, Sickle Cell/blood , Erythrocyte Indices , beta-Thalassemia/blood , Adolescent , Adult , Cell Differentiation , Female , Ferritins/blood , Humans , Male , Middle Aged , Mutation , ROC Curve , Receptors, Transferrin/blood , Sequence Analysis, DNA , Young Adult , beta-Thalassemia/genetics
5.
Ann Biol Clin (Paris) ; 70(3): 295-8, 2012.
Article in English | MEDLINE | ID: mdl-22565177

ABSTRACT

In this study we report the fortuitous description of hemoglobin (Hb) Hope in a Tunisian athlete. This Hb is one of hemoglobin variants that show a lower stability and oxygen affinity that is beneficial to tissue oxygen delivery. Hb Hope was isolated by automated high performance liquid chromatography and was unequivocally found to be Hb Hope using DNA-based methods: polymerase chain reaction, denaturing gradient gel electrophoresis, direct DNA sequencing. Restriction haplotype showed that this Hb was supported by the Mediterranean haplotype I. Hb Hope was identified at first in a black African-American family and later in several other black and non black ethnic groups. All these descriptions raise the question of the Hb Hope origin. Recently, Hb Hope was reported in Thai in association with the same Mediterranean haplotype I. This favors that Tunisian and Thai Hb Hope would share a common Mediterranean origin, thus suggesting the possibility of a Mediterranean gene flow. On another hand, the observation of Hb Hope in a high level athlete would suggest a selection pressure of this Hb variant due to higher physical aptitude.


Subject(s)
Athletes , Hemoglobins, Abnormal/analysis , Hemoglobins, Abnormal/genetics , Adult , Athletic Performance/physiology , Base Sequence , Female , Humans , Incidental Findings , Inheritance Patterns/physiology , Molecular Diagnostic Techniques , Tunisia
6.
Mol Biol Rep ; 39(4): 4619-25, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21947948

ABSTRACT

Hereditary persistence of fetal hemoglobin (HPFH) is a group of genetically heterogeneous conditions characterized by continued expression of fetal hemoglobin (HbF) in adulthood. HPFH may be due not only to point mutations or large deletions in different regions of the cluster ß globin, but also to variations in several polymorphic sequences in this cluster. The objective of this work was to evaluate effects of polymorphic markers within cluster ß globin on HbF expression. For the purpose, we have explored in this first study of Tunisian HPFH four polymorphic regions of ß globin cluster in 68 healthy adults (34 subjects with high levels of HbF and 34 with normal HbF levels). Our results showed that the increase of HbF levels is associated with the -158 Gγ C â†’ T polymorphism, the TG(18)CG(2)CACG, TC TG(9)AG TG(2)CG(2) and TG(11)CG(4) configurations in the second intron of Gγ gene and the -540 ß (AT)(6)T(9) and (AT)(7)T(8) repeated sequences. Among the 34 subjects with raised levels of HbF, approximately 97% carried one or more of these six markers. This study suggests that there is a significant association between certain polymorphic configurations of the ß globin cluster and the increase of HbF levels in healthy individuals.


Subject(s)
Fetal Hemoglobin/metabolism , Multigene Family/genetics , Polymorphism, Genetic , beta-Globins/genetics , Adolescent , Adult , Alleles , Female , Gene Frequency/genetics , Genetic Markers , Humans , Male , Middle Aged , Nucleotide Motifs/genetics , Phenotype , Promoter Regions, Genetic/genetics , Sequence Analysis, DNA , Young Adult
7.
Blood ; 118(4): 884-93, 2011 Jul 28.
Article in English | MEDLINE | ID: mdl-21628399

ABSTRACT

Patients with ß-thalassemia require lifelong iron chelation therapy from early childhood to prevent complications associated with transfusional iron overload. To evaluate long-term efficacy and safety of once-daily oral iron chelation with deferasirox, patients aged ≥ 2 years who completed a 1-year, phase 3, randomized trial entered a 4-year extension study, either continuing on deferasirox (deferasirox cohort) or switching from deferoxamine to deferasirox (crossover cohort). Of 555 patients who received ≥ 1 deferasirox dose, 66.8% completed the study; 43 patients (7.7%) discontinued because of adverse events. In patients with ≥ 4 years' deferasirox exposure who had liver biopsy, mean liver iron concentration significantly decreased by 7.8 ± 11.2 mg Fe/g dry weight (dw; n = 103; P < .001) and 3.1 ± 7.9 mg Fe/g dw (n = 68; P < .001) in the deferasirox and crossover cohorts, respectively. Median serum ferritin significantly decreased by 706 ng/mL (n = 196; P < .001) and 371 ng/mL (n = 147; P < .001), respectively, after ≥ 4 years' exposure. Investigator-assessed, drug-related adverse events, including increased blood creatinine (11.2%), abdominal pain (9.0%), and nausea (7.4%), were generally mild to moderate, transient, and reduced in frequency over time. No adverse effect was observed on pediatric growth or adolescent sexual development. This first prospective study of long-term deferasirox use in pediatric and adult patients with ß-thalassemia suggests treatment for ≤ 5 years is generally well tolerated and effectively reduces iron burden. This trial was registered at www.clinicaltrials.gov as #NCT00171210.


Subject(s)
Benzoates/therapeutic use , Chelation Therapy/methods , Iron Chelating Agents/therapeutic use , Triazoles/therapeutic use , beta-Thalassemia/drug therapy , Adolescent , Adult , Benzoates/administration & dosage , Benzoates/adverse effects , Chelation Therapy/adverse effects , Child , Child, Preschool , Cross-Over Studies , Deferasirox , Deferoxamine/therapeutic use , Female , Follow-Up Studies , Growth and Development/drug effects , Humans , Iron/metabolism , Iron Chelating Agents/administration & dosage , Iron Chelating Agents/adverse effects , Male , Middle Aged , Triazoles/administration & dosage , Triazoles/adverse effects , Young Adult
8.
Ann Hum Biol ; 38(5): 561-3, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21329479

ABSTRACT

BACKGROUND: There are few data on the molecular basis of Cystic Fibrosis (CF) in North Africa, probably due to under-diagnosis. AIM: This is the first study of cystic fibrosis transmembrane conductance regulator (CFTR) mutations in the Libyan population. SUBJECTS AND METHODS: This study analysed the complete coding region and flanking intronic sequences of the CFTR gene in 10 unrelated Libyan CF patients. RESULTS: This study identified four mutations (F508del, c.1670delC, N1303K and E1104X), with a high frequency of the latter. CONCLUSION: Identification of CF mutations facilitates molecular investigation of cystic fibrosis in the Libyan population and helps to provide effective genetic counselling among CF families.


Subject(s)
Cystic Fibrosis/genetics , Mutation/genetics , Child , Child, Preschool , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Female , Genotype , Humans , Infant , Infant, Newborn , Libya , Male
9.
Eur J Appl Physiol ; 108(6): 1075-81, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20013288

ABSTRACT

The aim of this study was to determine the prevalence and nature of hemoglobin (Hb) defects in a Mediterranean high-level (HL) athlete population. Five hundred and ninety-four HL male and female athletes were recruited during the annual follow-up of the members of Tunisian national teams. Hematological data, Hb electrophoresis, and DNA analysis were assessed using conventional techniques. Sporting discipline, type of sport, and performance levels were assessed using a questionnaire. The results showed that 32 HL athletes had abnormal Hb (5.4%): beta-thalassemia (2.2%), alpha-thalassemia (0.5%), HbAS (1.5%), HbAC (0.5%), and rare Hb variants (0.7%). Of the 32 defect carriers, all but one (a alpha-thalassemia) were heterozygous. All the detected hemoglobinopathies but one (an Hb Hope) had already been reported in the country. The prevalence of Hb defect in the HL athletes was similar to that described in the general Tunisian population (P > 0.05). The percentage of Hb defect in the athletes was not dependent on gender, or performance level (P > 0.05). Within each type of sport the percentages of athletes with normal and abnormal Hb were similar (P > 0.05). The hematological data revealed the diversity of anemia, microcytosis, and hypochromia in thalassemic HL athletes. We concluded that HL athletes in Tunisia were a representative sample of the general Tunisian population regarding the prevalence and nature of benign abnormal Hb. The hematological data of the thalassemia carriers exhibited high variability and raised the question of genetic and sporting counseling, as well as biological follow-up for these carriers.


Subject(s)
Hemoglobinopathies/epidemiology , Sports/statistics & numerical data , Adolescent , Adult , Child , Female , Humans , Male , Mediterranean Region/epidemiology , Prevalence , Risk Assessment/methods , Risk Factors , Sex Distribution , Tunisia/epidemiology , Young Adult
10.
Genet Test Mol Biomarkers ; 13(5): 577-81, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19715466

ABSTRACT

AIM: To determine the frequency and types of mutations causing cystic fibrosis (CF) in Tunisia. METHODS: We analyzed the complete coding region and flanking intronic sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 68 unrelated patients suffering from the classical form of the disease. RESULTS: Twelve different CFTR mutations accounted for 90% (123/136) of CF alleles, including F508del (47.06%), E1104X (16.18%), N1303K (6.62%), 711 + 1T > G (5.88%), W1282X (4.41%), G542X (3.67%), R1158X (1.47%), 4016insT (0.74%), and R785X (0.74%). Three novel mutations were detected in this study: I1203V (1.47%), 1811 + 5A > G (0.74%), and 4268 + 2T > G (1.47%). Fifty patients (74%) were homozygous, among which 28 (41.17%) for F508del and 10 (14.7%) for E1104X. CONCLUSIONS: Ninety-seven percent of patients were found with at least one CFTR mutation. This study contributes to a better knowledge on CF-causing mutations in different regions in Tunisia and demonstrates that a complete scanning of CFTR sequences is necessary to implement efficient programs for CF genetic screening and counseling in this part of North Africa.


Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis/genetics , Mutation , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Tunisia
11.
Hemoglobin ; 33(3): 163-76, 2009.
Article in English | MEDLINE | ID: mdl-19657830

ABSTRACT

Hemoglobin (Hb) disorders are common, potentially lethal monogenic diseases, posing a global health challenge. With worldwide migration and intermixing of carriers, demanding flexible health planning and patient care, hemoglobinopathies may serve as a paradigm for the use of electronic infrastructure tools in the collection of data, the dissemination of knowledge, the harmonization of treatment, and the coordination of research and preventive programs. ITHANET, a network covering thalassemias and other hemoglobinopathies, comprises 26 organizations from 16 countries, including non-European countries of origin for these diseases (Egypt, Israel, Lebanon, Tunisia and Turkey). Using electronic infrastructure tools, ITHANET aims to strengthen cross-border communication and data transfer, cooperative research and treatment of thalassemia, and to improve support and information of those affected by hemoglobinopathies. Moreover, the consortium has established the ITHANET Portal, a novel web-based instrument for the dissemination of information on hemoglobinopathies to researchers, clinicians and patients. The ITHANET Portal is a growing public resource, providing forums for discussion and research coordination, and giving access to courses and databases organized by ITHANET partners. Already a popular repository for diagnostic protocols and news related to hemoglobinopathies, the ITHANET Portal also provides a searchable, extendable database of thalassemia mutations and associated background information. The experience of ITHANET is exemplary for a consortium bringing together disparate organizations from heterogeneous partner countries to face a common health challenge. The ITHANET Portal as a web-based tool born out of this experience amends some of the problems encountered and facilitates education and international exchange of data and expertise for hemoglobinopathies.


Subject(s)
Hemoglobinopathies/therapy , Information Systems , Research Design , Thalassemia/therapy , Europe , Geography , Humans , International Cooperation , Internet , Mediterranean Region
12.
Mediterr J Hematol Infect Dis ; 1(1): e2009005, 2009 Nov 10.
Article in English | MEDLINE | ID: mdl-21415987

ABSTRACT

Hemoglobinopathies are a group of inherited hemoglobin disorders. Initially described in the subtropical regions, they are now spread all around the world because of migration. Their high frequency and clinical severity make them a major public health problem mostly in Africa due to the limited resources reserved for the management and prevention of these diseases. Despite considerable advances in the control and management of the hemoglobinopathies, therapeutic approach and follow- up still pose problems because of the major economic and organizational difficulties in the developing countries, particularly in Africa where problems are majored by other factors including social and cultural backgrounds, high consanguinity, as well as the coexistence of infection and malnutrition. Effective prevention programs have been carried out successfully in many European countries concerned by hemoglobinopathies. They should be extended to African regions where hemoglobin disorders account for more than 70% of total hemoglobinopathies in the world. Prevention should remain the major priority of health services to reduce incidence of hemoglobinopathies in Africa. Hereby we present the Tunisian experience that may reflect globally the profile of the prevention evolution of hemoglobinopathies in North Africa.

13.
Tunis Med ; 86(6): 567-72, 2008 Jun.
Article in French | MEDLINE | ID: mdl-19216450

ABSTRACT

AIM: The aim of this report is to determine clinical characteristics and outcome of Cystic Fibrosis (CF). METHODS: Cases of CF managed at Infantile Medicine A Department in Children's Hospital of Tunis during 13 years (1994-2006) were reviewed. RESULTS: 16 children had CF. They were 8 males and 8 females. 13 patients were consanguineous and four had similar familial cases. The mean age at diagnosis was 19 months (10 days, 13 years). 3/4 of patients were symptomatic within the first trimester of life. Revealing symptoms were: obstructive bronchopathy associated to chronic diarrhea (n=6), edema-anemia-hypotrophy-hypoproteinemia syndrome (n=3), meconium ileus (n=4), bronchiectasis (n=2) and chronic diarrhea (n=1). The diagnosis was confirmed by sweat test and genotypic data. The F508 del was the most frequent mutation (54%). Clinical outcome was characterized by the occurrence of respiratory and nutritional complications: acute respiratory failure (n=6), chronic respiratory failure (n=3), chronic pseudomonas aeruginosa infection (n=6) at a medium age of 3.8 years, recurrent haemoptysis (n=2), pleural effusion (n=2), a malnutrition (n =10) and diabetes associated to puberty delay in one patient. Seven patients died at mean age of 4.4 years (6 months, 17.3 years). Among surviving patients, six had no compromised nutritional status or lung function. Prenatal diagnosis was performed in three families. CONCLUSION: CF is characterized by earliest onset and severity of symptoms. Therapeutic insufficiency is the main cause of precocious complications and poor prognosis in our series.


Subject(s)
Cystic Fibrosis/diagnosis , Adolescent , Bronchiectasis/etiology , Child , Child, Preschool , Chronic Disease , Consanguinity , Cystic Fibrosis/complications , Cystic Fibrosis/genetics , Cystic Fibrosis/mortality , Cystic Fibrosis/therapy , Diarrhea/etiology , Female , Genotype , Hospitals, Pediatric , Humans , Ileus/etiology , Infant , Infant, Newborn , Intestinal Obstruction/etiology , Male , Meconium , Mutation , Nutritional Status , Prognosis , Respiratory Insufficiency/etiology , Retrospective Studies , Survival Analysis , Sweat/chemistry
15.
Hemoglobin ; 30(4): 437-47, 2006.
Article in English | MEDLINE | ID: mdl-16987798

ABSTRACT

We here present the first report of the detection of two rare beta0-thalassemia (thal) mutations in the Tunisian population: codon 47 (+A) and codons 106/107 (+G). To the best of our knowledge this is the second report of the codon 47 (+A) mutation, the first being identified in a Surinamese subject. The codons 106/107 (+G) mutation was first described in American Blacks, subsequently in Egyptians and Palestinians, and now in Tunisians. These mutations were detected by denaturing gradient gel electrophoresis (DGGE) screening followed by automated nucleotide sequencing. The former was found in two related beta-thal major patients in the homozygous state, while the latter was identified in a homozygous state in a transfusion-dependent beta-thal subject and in a sickle cell beta-thal patient. Both mutations are in linkage disequilibrium with haplotype V and sequence framework 2. Given the known wide spectrum of beta-thal alleles in the Tunisian population, the present report further confirms such heterogeneity. The knowledge of an updated spectrum of beta-thal alleles in Tunisia must allow the implementation of a more efficient screening strategy for genetic counseling and prenatal diagnosis.


Subject(s)
Globins/genetics , Haplotypes/genetics , Linkage Disequilibrium/genetics , Point Mutation/genetics , beta-Thalassemia/genetics , Adolescent , Adult , Child , Codon, Nonsense/genetics , DNA Fingerprinting , DNA Mutational Analysis , Female , Frameshift Mutation/genetics , Hemoglobin, Sickle/genetics , Humans , Male , Phenotype , Sequence Analysis, DNA , Tunisia
16.
Hemoglobin ; 30(2): 175-81, 2006.
Article in English | MEDLINE | ID: mdl-16798642

ABSTRACT

The polymorphism of the beta-globin gene haplotypes and frameworks are useful in the determination of the unicentric and multicentric origin of a mutational event. In order to improve our knowledge of the chromosomal background of the beta-globin gene in three beta-thalassemia (thal) mutations originally reported in Tunisia, namely codons 25/26 (+T), codon 30 (G-->C) and IVS-I-2 (T-->G), we have investigated 13 unrelated individuals. There were five non transfusion-dependent patients homozygous for the IVS-I-2 (T-->G) mutation, five others were homozygous for the codon 30 (G-->C) mutation, one was a homozygote for the codons 25/26 (+T) insertion mutation and one patient was a compound heterozygote for the codon 39 (C-->T) and codon 25/26 (+T) mutations; the last patient had a betaS/codon 25/26 (+T) compound heterozygous genotype. Haplotype analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based methods. The framework polymorphism was established by direct sequencing. beta-Globin gene analyses demonstrated that all IVS-I-2 (T-->G) cases were associated with haplotype IX; the codon 30 (G-->C) mutation was supported by haplotype I, while the codons 25/26 (+T) mutation was linked to haplotypes I and IX.


Subject(s)
Globins/genetics , Haplotypes/genetics , Mutation , beta-Thalassemia/genetics , Codon/genetics , DNA Mutational Analysis , Ethnicity/genetics , Female , Heterozygote , Homozygote , Humans , Male , Mutagenesis, Insertional , Mutation, Missense , Pedigree , Phenotype , Point Mutation , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Sickle Cell Trait/complications , Sickle Cell Trait/genetics , Tunisia , beta-Thalassemia/complications
17.
Blood ; 107(9): 3455-62, 2006 May 01.
Article in English | MEDLINE | ID: mdl-16352812

ABSTRACT

Deferasirox (ICL670) is a once-daily oral iron chelator developed for the treatment of chronic iron overload from blood transfusions. A comparative phase 3 trial was conducted to demonstrate the efficacy of deferasirox in regularly transfused patients with beta-thalassemia aged 2 years or older. Patients were randomized and received treatment with deferasirox (n = 296) or deferoxamine (n = 290), with dosing of each according to baseline liver iron concentration (LIC). The primary endpoint was maintenance or reduction of LIC; secondary endpoints included safety and tolerability, change in serum ferritin level, and net body iron balance. In both arms, patients with LIC values of 7 mg Fe/g dry weight (dw) or higher had significant and similar dose-dependent reductions in LIC and serum ferritin, and effects on net body iron balance. However, the primary endpoint was not met in the overall population, possibly due to the fact that proportionally lower doses of deferasirox relative to deferoxamine were administered to patients with LIC values less than 7 mg Fe/g dw. The most common adverse events included rash, gastrointestinal disturbances, and mild nonprogressive increases in serum creatinine. No agranulocytosis, arthropathy, or growth failure was associated with deferasirox administration. Deferasirox is a promising once-daily oral therapy for the treatment of transfusional iron overload.


Subject(s)
Benzoates/therapeutic use , Iron Chelating Agents/therapeutic use , Triazoles/therapeutic use , beta-Thalassemia/drug therapy , Administration, Oral , Adolescent , Adult , Benzoates/administration & dosage , Benzoates/adverse effects , Child , Child, Preschool , Deferasirox , Deferoxamine/therapeutic use , Drug Administration Schedule , Female , Humans , Iron/metabolism , Iron Chelating Agents/administration & dosage , Iron Chelating Agents/adverse effects , Liver/metabolism , Male , Middle Aged , Safety , Triazoles/administration & dosage , Triazoles/adverse effects , beta-Thalassemia/metabolism
18.
Tunis Med ; 84(11): 687-96, 2006 Nov.
Article in French | MEDLINE | ID: mdl-17294892

ABSTRACT

The hemoglobinopathies affect the blood red cells and are the most common monogenic diseases worldwide. The high frequency and clinical severity of the hemoglobinopathies, make them a major public health problem. We report here an updated review on epidemiologic and molecular data of the hemoglobinopathies in Tunisia. From 1980 to 2005, a screening of hemoglobinopathies was performed on a total of 44299 individuals according to 2 kinds of work: a systematic screening on several populations (24240) from different regions of the country and a cohort of individuals referred to our laboratory for hemoglobinopathies suspicion (20059). Blood was collected in EDTA tubes from the studied individuals to determine the hematological parameters, the hemoglobin electrophoretic data and the iron status. DNA analysis was performed by the usual PCR based-procedures for the molecular defects identification. Systematic surveys allowed us to show an average prevalence of hemoglobinopathy carriers of 4.48% reaching 12.50% in some focus regions. The average frequency of B-thal trait is of 2.21% and that of sickle cell trait is of 1.89%. Hemoglobin screening on newborns has shown a frequency of alpha-thal trait of 5.48%. Oriented studies from our hospital experience allowed us to list more than 2394 major forms. Molecular analysis on beta-thalassemia patients allowed to identify 21 different alleles. The two most frequent mutations (cd39 C-->T and IVS1-110 G-->A) accounted for 70% of the total encountered beta-thal mutations. Among the other mutations, three were described for the first time in the world on Tunisian families. The sickle cell disease is associated with the Benin haplotype in 95% of the studied cases. Concerning alpha-thal mutation, the - alpha37 deletion was the most common. We also note the identification of several rare Hemoglobin variants as well as diverse associated forms of anomalies. Knowledge of epidemiological and molecular data of hemoglobinopathies is fundamental to understand the mechanisms of disease expression and the genotype / phenotype correlations. Furthermore, the distribution of the hemoglobinopathies in the regions allows to orientate efficiently the planning tasks regarding control and prevention of these hereditary diseases.


Subject(s)
Hemoglobinopathies/epidemiology , Hemoglobinopathies/genetics , Anemia, Sickle Cell/epidemiology , Anemia, Sickle Cell/genetics , Cohort Studies , Genotype , Health Surveys , Hemoglobins, Abnormal/genetics , Humans , Infant, Newborn , Mass Screening , Mutation , Phenotype , Prevalence , Tunisia/epidemiology , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics
19.
Tunis Med ; 83(9): 511-8, 2005 Sep.
Article in French | MEDLINE | ID: mdl-16383194

ABSTRACT

Anemia continue to be prevalent among children under five years despite the improvement of socioeconomic and sanitary indicators. The purpose of the present cross-sectorial study is to assess the etiologic factors responsible for anemia. Knowledge of the relative importance of the different causes should form a basis for intervention strategies to prevent and control anemia. The survey covered 955 children under the age of five years, native of two regions with the highest prevalent of anemia, the Southwest and the District of Tunis. The results showed that 29% of children suffered from anemia. About 70% of them were iron deficient. The fractions of the deficiency in vitamin B12 and in folates were insignificant. Only 3% of children had chronic inflammation associated with (and possibly responsible for) their anemia A little fraction of anemia (approximately 5%) was due to thalassemia or drepanocytosis. Picawasan important causal factor of iron deficiency anemia. The parasites identified instool could not cause anemia.


Subject(s)
Anemia, Iron-Deficiency/epidemiology , Anemia, Iron-Deficiency/etiology , Child, Preschool , Chronic Disease , Female , Health Surveys , Humans , Inflammation , Male , Nutritional Status , Prevalence , Tunisia/epidemiology
20.
Hemoglobin ; 29(4): 263-8, 2005.
Article in English | MEDLINE | ID: mdl-16370486

ABSTRACT

Herein we describe the case of a Tunisian girl who presented with 3% Hb Bart's (gamma4) at birth. At the age of 3 years, she showed microcytosis and hypochromia in the absence of iron deficiency. The first step of molecular analysis was to test for the common Mediterranean mutations and the classical -alpha3.7 deletion was found in the heterozygous state. Since this finding could not explain the level of Hb Bart's at birth, or the hypochromia and microcytosis, all the alpha-globin genes were sequenced. This revealed a rare point mutation at codon 119 (CCT-->TCT) in the alpha1-globin gene, identified for the first time in Tunisia, and which has previously been described as an unstable hemoglobin (Hb) variant named Hb Groene Hart [alpha119(H2)Pro-->Ser (alpha1)]. Here the -alpha3.7/alpha(alpha)119(CCT-->TCT) genotype is responsible for the alpha-thalassemia (thal) trait phenotype.


Subject(s)
Globins/genetics , Hemoglobins, Abnormal/genetics , Point Mutation , alpha-Thalassemia/genetics , Child, Preschool , Family Health , Female , Humans , Sequence Deletion , Tunisia
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