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S Fattoum

Publications and source records attributed to S Fattoum.

At least 19 recordsLinked to original sources
PubMed2003

HbHope/HbS and HbS/beta-thal double compound heterozygosity in a Mauritanian family: clinical and biochemical studies.

The hemoglobin Hope was discovered in a Mauritanian family that comes from Gorgol in the southwest of the country. The family belongs to the Soninké ethnic group, which is one of the black population groups in Mauritania. Along with this abnormal hemoglobin, HbS and beta-thalassemia were also found. This family, which we refer to as D, was encountered during a survey we conducted to study hemoglobinopathies in Mauritania. First the father was identified to carry an association of HbS and HbHope, then the study was extended to the entire family members: the wife who was found to have a beta-thalassemia trait and their three children who were found to carry HbS/beta-thalassemia mutations each. All together this family carries three different mutations that resulted in a double compound heterozygosity HbHope/HbS and HbS/beta-thal.

DNA Mutational Analysis↗
PubMed2002

Hemoglobin A2' (HbA2delta') in the Mauritanian population: first results of a preliminary survey.

The Mauritanian population consists of two main groups: one Arab and Berber population and one of Black African origin. The latter includes five ethnic groups: Pular, Soninke, Black Maurs, Wolof, and Bambara. Abnormal HbA2 was found in the Mauritanian population and was characterized by cellulose acetate electrophoresis at pH 8.4 followed by DNA analysis. Among 785 subjects examined, 17 were carriers of HbA2' corresponding to 2.16 percent. The highest frequency was observed among the Pular (3.09 percent), the Black Maurs (2.72 percent), the Wolof (2.27 percent), and the Soninke (2.04 percent).

Adult↗
PubMed2002

Epidemiological profile of hemoglobinopathies in the Mauritanian population.

We performed a study of hemoglobin in 700 blood donors attending the Centre Hospitalier National de Nouakchott in Mauritania. We detected 116 cases of anomalies corresponding to a global prevalence of 16.6%. The analysis of the samples studied showed that 72.3 % of the donors were Blacks and 28.7 % were White Maurs ( Maures blancs). In the Black population the prevalence of hemoglobinopathies is 21.44% whereas among the White Maurs it is 4.47%. In this study, the six ethnic groups that constitute the Mauritanian population were also represented in the sample, but with different numbers. We noted some differences in the repartition of anomalies among these groups. The hemoglobin anomalies that were found are sickle cell anemia, beta-thalassemia, and delta-variant, all in heterozygous form. Geographical repartition revealed that the hemoglobin abnormalities are mostly encountered in the Southeast and the Southwestern parts of the country, which could be considered areas of high risk for hemoglobinopathies.

Blood Donors↗
PubMed1999

The erythrocyte effects of haemoglobin O(ARAB).

To test the hypothesis that HbOARAB induces an increase in red cell mean corpuscular haemoglobin concentration (MCHC), we studied members of four Tunisian families who were either homo- or heterozygous for HbOARAB or were double heterozygotes for HbS and HbOARAB. The alpha-gene status was also tested. The findings included: (1) Distinctive variation in red cell density (MCHC) as determined by separation of red cells on isopycnic gradients: (a) All red cells from patients homozygous for HbOARAB were denser than normal red cells, as is observed for homozygous HbC patients. (b) In patients heterozygous for HbOARAB, red cell density was strongly influenced by the presence of alpha-thalassaemia. The coexistence of -alpha/alphaalpha resulted in an average red cell density slightly greater than normal (AA) red cells. Patients heterozygous for HbOARAB with a normal complement of four alpha genes had denser red cells similar to sickle cell disease with some cells of normal density but with most cells very dense. (c) Finally, the double heterozygotes for HbS and HbOARAB had significant haemolytic anaemia and red cells denser than normal with some as dense as the densest cells found in sickle cell anaemia. (2) Reticulocytes in patients homozygous for HbOARAB were found in the densest density fraction of whole blood. (3) Cation transport in patients homozygous for HbOARAB was abnormal, with K:Cl cotransport activity similar to that of HbS-Oman and only somewhat lower than in sickle cell anaemia red cells. The activity of the Gardos channel was indistinguishable from that found in HbS, HbC and HbS-Oman cells. We conclude that the erythrocytic pathogenesis of HbOARAB involves the dehydration of red cells due, at least in part, to the K:Cl cotransport system. The similarity of the charge and consequences of the presence of both HbC and HbOARAB, which are the products of mutations at opposite ends of the beta-chain, raises the possibility that this pathology is the result of a charge-dependent interaction of these haemoglobins with the red cell membrane and/or its cytoskeleton and that this abnormality is present early in red cell development.

Adolescent↗
PubMed1999

[Contributions to the sociologic analysis of the impact of sickle cell disease on families from Northern Tunisia].

The improvement of the conditions of care and quality of life of people living with drepanocytosis now constitutes a major concern of health authorities and voluntary groups (associations of sick people and their parents). In order to examine the conditions and methods of care for children living with drepanocytosis in the Bizerte region of Northern Tunisia and to understand the problems and difficulties experienced by them and their families in their daily lives, an anthropological study was carried out in the region between January 16 and February 12, 1997. Thirty-three interviews were carried out with families of infected children. The interviews were semi-directive using a pre-established protocol (interview guide). Thirty interviews were then analysed. A multitude of information concerning various medical and psycho-social aspects of drepanocytosis in the region were revealed. The data were regrouped into the following categories: circumstances of discovering the illness; explicative model of the illness as perceived by the people interviewed; conditions and methods of care of the sick child; degree of satisfaction with the health care system; psychological profile of the children interviewed; educational level of the children interviewed; repercussions the illness has on the family; impact of the illness on household budget; suggestions and comments of the people interviewed. In light of the information collected, various actions have been proposed with the goal of improving the conditions of care and quality of life of people living with drepanocytosis in the region.

Anemia, Sickle Cell↗
PubMed1998

Antiphospholipid antibodies: lupus anticoagulants, anticardiolipin and antiphospholipid isotypes in patients with sickle cell disease.

Antiphospholipid antibodies were investigated in 37 individuals with sickle cell disease and compared to a control group of 30 healthy subjects. Sickle cell patients included 18 homozygous sickle cell patients, 8 S/beta thalassemic patients and 11 sickle cell trait subjects. In all individuals, antiphospholipid antibodies were explored by lupus anticoagulant (LA) detection and the quantification of IgG and IgM anticardiolipin (aCL) isotypes, total antiphospholipid antibodies (APA) and IgM, IgG and IgA antiphospholipid classes. In homozygous sickle cell patients, mean level of IgG aCL and total APA were significantly increased (17.02 +/- 8.88 GPL/ml, p < 0.05 and 10.64 +/- 10.58 UPL/ml, p < 0.05 respectively). The IgG aCL, total APA and LA frequencies were 22.2%, 44.4% and 62.2%, respectively. APA isotypes were mostly IgG or IgG and IgA. In S/beta thalassemic patients, mean levels of APA were significantly increased (10.81 +/- 7.82 UPL/ml, p< 0.05). Their frequency was 71.4% and they were mostly IgG or IgG and IgA. In patients with sickle cell trait, mean levels of APA were significantly increased (10.84 +/- 5.84 UPL/ml, p < 0.01). Their frequency was 72.7% and mostly of IgG isotype. Our study showed a close association between high APA levels and sickle cell syndrome, however there was no relationship between high levels of antiphospholipid antibodies and the major complications of sickle cell disease.

Adolescent↗
PubMed1997

Fibrinolytic response to venous occlusion in patients with homozygous sickle cell disease.

The fibrinolytic potential was evaluated in 37 patients with homozygous sickle cell disease and compared to a control group of 30 age- and sex-matched healthy volunteers. In all individuals, the euglobulin clot lysis time and plasma antigen levels of t-Pa and PAI-1 were measured before and after venous occlusion (v.o) for 10 min. The global fibrinolytic activity was normal in 4 patients (good responders to v.o), while it was decreased in 33 patients (poor responders to v.o). Among the latter, 22 patients had significantly increased baseline levels of PAI-1 Ag (82.6 +/- 27.5 ng/ml, p < 0.001) and a normal release of t-Pa Ag after v.o. In contrast, 11 patients had basal values of PAI-1 Ag comparable to those in controls with a defective release of t-Pa Ag after v.o (11.4 +/- 5.2 ng/ml, p < 0.01). These data provide evidence for reduced fibrinolytic capacity resulting from either increased basal levels of PAI-1 or defective release of t-PA.

Adolescent↗
PubMed1996

Abnormalities of coagulation and fibrinolysis in homozygous sickle cell disease.

Abnormalities of coagulation and fibrinolysis were studied in a group of 28 children and young adults with homozygous sickle cell disease (SCD), either in the steady state (n = 12) or during painful crisis (n = 16). Coagulation was explored by standard clotting tests and by measurement of prothrombin complex factors, factor VIII (VIII:C) and antithrombin III (ATIII), protein C (PC) and protein S (PS) activities, while fibrinolytic potential was evaluated using D-dimer, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1) assays. In SCD patients, thrombin time (TT) was constantly shortened, both in the steady state (ratio to control 0.83 +/- 0.08, p < 0.0001) and in crisis (0.76 +/- 0.06, p < 0.0001). Mean levels of prothrombin complex were similar in asymptomatic patients to those in controls, but were significantly decreased during sickle cell crisis (p < 0.05 for factor V and p < 0.0001 for factors II, VII and X). Factor VIII:C was significantly increased, both in the steady state (207 +/- 35%, p < 0.0001) and during crisis (208 +/- 34%, p < 0.0001). PS activity was reduced int he steady state (81 +/- 12%, p < 0.01) and further diminished in crisis (68.5 +/- 27.5%, p < 0.001), while D-dimers were significantly elevated during sickle cell crisis (1028 +/- 675 ng/ml, p < 0.001). In all SCD patients, baseline levels of t-PA antigen were comparable to those in controls, whereas concentrations of PAI-1 antigen were significantly increased, either in the steady state (89.7 +/- 26.3 ng/ml, p < 0.0001) or in crisis (75.0 +/- 24.8 ng/ml, p < 0.0001). These results provide evidence for the presence of circulating activated clotting factors in SCD and for an imbalance of the profibrinolytic and antifibrinolytic systems most likely due to increased PAI-1 levels.

Adolescent↗
PubMed1996

Distribution of CFTR mutations in cystic fibrosis patients of Tunisian origin: identification of two novel mutations.

Cystic fibrosis (CF), the most common lethal genetic disease in the Caucasian population, is caused by mutations in the CF transmembrane conductance regulator gene (CFTR). More than 500 molecular defects have been reported to date. The distribution of these mutations is both heterogeneous and population related. In Mediterranean populations, 20-30% of CF alleles remain unidentified. We have studied a sample of 39 CF patients of Tunisian origin and have used a GC clamp DGGE assay to scan the CFTR gene. Two novel mutations have been found, but we have been unsuccessful in finding any mutation in 40% of these alleles. These results suggest that, in this Mediterranean population, additional mutations may lie elsewhere in the promoter region or in introns not yet analyzed.

Alleles↗
PubMed1995

A point mutation in the protein 4.2 gene (allele 4.2 Tozeur) associated with hereditary haemolytic anaemia.

A recessively transmitted haemolytic anaemia associated with the lack of protein 4.2 was found in a Tunisian kindred. Trace amounts of this protein (72 kD component) became visible using high-sensitivity Western blots. Band 3 and ankyrin genes were excluded as candidate genes by linkage studies, and nucleotide sequencing of band 3 cytoplasmic domain cDNA revealed no alteration. In contrast, protein 4.2 gene contained in the homozygous state a mutation at position 310: CGA-->CAA (Arg-->Gln). This mutation defining allele 4.2 Tozeur was co-inherited with the disease. The mRNA encoding the variant protein was normal in size and approximately normal in amount. Recombinant protein 4.2 Tozeur bound normally to red cell IOVs but disclosed an increased susceptibility to proteolysis in vitro. We infer that the nearly total absence of protein 4.2 in the patients results from imbalance between destruction and synthesis of mutated protein 4.2 prior to its binding to the membrane.

Anemia, Hemolytic↗
PubMed1994

Puzzling biochemical thyroid profile in patients with multinodular goitre originating from a mild iodine deficient area in Tunisia.

Thirty Tunisian patients with a voluminous multinodular goiter with cold nodules and inhabiting a region of mild iodine deficiency, have been studied. The 131 I fixation by the thyroid, three hours after ingestion was significatively higher than in normal population. Fourty six per cent of the patients have stable iodine urine contents less or equal to 0.39 mumol/L. Three serum concentrations were paradoxically abnormal: thyrotropin (TSH), thyroglobulin (TG) and gammaglobulin concentrations. Fourty seven per cent of the serum thyrotropin (TSH) levels were less than the normal values though the serum total triiodotyronine (TT3), tetraiodotyronine (TT4), free triiodotyronine (FT3), free tetraiodotyronine (FT4), antithyroglobulin antibodies, total protein, triglycerides and cholesterol concentrations were normal. Serum thyroglobulin (TG) rates were elevated, ranged from 2 to 10,180 ng/ml and twenty five per cent of our patients showed levels greater than 500 ng/ml. The gammaglobulin levels were greater than normal in sixty eight per cent of our patients though only 10% of our patients manifest antithyroglobulin antibodies.

Adult↗
PubMed1993

[HbC/beta-thalassemia association. Eleven cases observed in Tunisia].

Eleven cases of simultaneous HbC hemoglobinopathy and beta-thalassemia were detected during a study of 11,200 subjects at high risk for inherited hemoglobin anomalies. In seven cases, main clinical manifestations were anemia and enlargement of the spleen, whereas the four other patients were apparently free of symptoms and were diagnosed during routine tests in family members of affected patients. Microcytosis and hypochromia were found in every case. Most of the patients were from the North-Western part of Tunisia. Blood transfusions were required in only one patient, who was an infant with HbC/beta + thalassemia.

Adolescent↗
PubMed1992

Beta S haplotypes in various world populations.

We have determined the beta S haplotypes in 709 patients with sickle cell anemia, 30 with SC disease, 91 with S-beta-thalassemia, and in 322 Hb S heterozygotes from different countries. The methodology concerned the detection of mutations in the promoter sequences of the G gamma- and A gamma-globin genes through dot blot analysis of amplified DNA with 32P-labeled probes, and an analysis of isolated Hb F by reversed phase high performance liquid chromatography to detect the presence of the A gamma T chain [A gamma 75(E19)Ile----Thr] that is characteristic for haplotype 17 (Cameroon). The results support previously published data obtained with conventional methodology that indicates that the beta S gene arose separately in different locations. The present methodology has the advantage of being relatively inexpensive and fast, allowing the collection of a vast body of data in a short period of time. It also offers the opportunity of identifying unusual beta S haplotypes that may be associated with a milder expression of the disease. The numerous blood samples obtained from many SS patients living in different countries made it possible to compare their hematological data. Such information is included (as average values) for 395 SS patients with haplotype 19/19, for 2 with haplotype 17/17, for 50 with haplotype 20/20, for 2 with haplotype 3/3, and for 37 with haplotype 31/31. Some information on haplotype characteristics of normal beta A chromosomes is also presented.

Africa↗
PubMed1992

Hb H disease caused by a homozygosity for the AATAAA-->AATAAG mutation in the polyadenylation site of the alpha 2-globin gene: hematological observations.

We have identified 7 patients with Hb H disease as homozygotes for a mutation in the polyadenylation site (AATAAA-->AATAAG) and have compared their hematological data with those of Hb H patients having other types of alpha-thalassemia determinants. All 7 patients exhibited moderate anemia with microcytosis and hypochromia being similar to that observed in the other patients. Relatives with a heterozygosity for this mutation are borderline microcytic and hypochromic without a significant anemia but with a low in vitro alpha/beta chain synthesis ratio. Analyses of the hemoglobin components identified low levels of Hb A2 and Hb H that were comparable to those found in other patients with Hb H disease; the level of the zeta-chain was low (average 0.14%).

Adolescent↗
PubMed1992

Hb Bab-Saadoun or alpha 2 beta (2)48(CD7)Leu----Pro, a mildly unstable variant found in an Arabian boy from Tunisia.

Hb Bab-Saadoun which has a Leu----Pro substitution at position 48 of the beta chain was detected in a young Arabian boy living in Tunisia. His parents did not have the variant which suggests that it occurred as a spontaneous mutation. The substitution is located in the interhelical CD segment; leucine at beta 48 is an invariable amino acid that may be important as part of a spacer sequence between the two helices and its replacement by proline may affect the stability of the hemoglobin molecule. Hb Bab-Saadoun is unstable in heat and isopropanol stability tests and its chain was best isolated by parachloromercuribenzoate precipitation. It appears unlikely that the presence of Hb Bab-Saadoun results in a hemolytic anemia.

Adolescent↗