Publications (6) View all
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Article: Allelic polymorphisms of human platelets-specific alloantigens in South Tunisian population.
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ABSTRACT: OBJECTIVES: Human platelet-specific alloantigens (HPA) are polymorphic epitopes which vary among ethnic groups. BACKGROUND: In Tunisia, HPA frequencies were determined in North and centre; however, the pattern of HPA in South Tunisian population is not been studied yet. The aim of this work was to determine allelic frequencies of HPA-1, -3, and -5 systems in south Tunisian population, in order to estimate the risk of anti-platelet allo-immunization and to create a register of HPA-typed blood donors. METHODS: Our study concerned 212 unrelated healthy, regular blood donors from southern Tunisia. Allelic polymorphisms of each system were determined using a polymerase chain reaction with sequence-specific primers. RESULTS: Genotype frequencies a/a, a/b, and b/b were, respectively, 0.670, 0.288, and 0.042 for HPA-1 system, 0.430, 0.462, and 0.108 for HPA-3 system, and 0.750, 0.241, and 0.009 for HPA-5 system. The allele frequencies were 0.814 and 0.186 for HPA-1a and -1b alleles; 0.660 and 0.340 for HPA-3a and -3b alleles and 0.870, and 0.130 for HPA-5a and -5b alleles. DISCUSSION: The reported frequencies are more similar to those of Caucasians than those of north Tunisian population.Hematology (Amsterdam, Netherlands) 04/2013; · 1.33 Impact Factor -
Chapter: Bernard Soulier Syndrome: A Genetic Bleeding Disorder
11/2011; , ISBN: 978-953-307-305-7 -
Article: Prevalence of factor V Leiden in south Tunisian blood donors.
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ABSTRACT: Venous thrombosis (VT) is a common disease with multifactorial pathogenesis. Factor V Leiden mutation (G1691A) (FVL) is the most common risk factor in venous thrombosis. The prevalence of FVL varies according to geography and ethnicity. Hence, in several countries there is a difference in the frequency of this mutation between the southern, central and north. In Tunisia, no data is available about prevalence of FVL mutation by geographical origin. For this reason, we sought the prevalence of FVL mutation in blood donor of south Tunisia population. FVL has been detected by APCR-test and confirmed by PCR-RFLP and sequencing. Two hundred fifty blood donors, different in age and sex were included in this study to determine the prevalence of FVL in blood donors. FVL mutation was found in 13.6% of the studied population. Thirty-one were heterozygous and three persons were homozygous with a rate of 12.4 and 1.2%, respectively. In conclusion, FVL mutation is very common in south Tunisian population.Journal of Thrombosis and Thrombolysis 03/2011; 32(1):116-9. · 1.48 Impact Factor -
Article: The same genetic defect in three Tunisian families with Bernard Soulier syndrome: a probable founder Stop mutation in GPIbbeta.
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ABSTRACT: GPIbα, GPIbβ, and GPIX are three candidate genes for a rare genetic bleeding disorder named Bernard Soulier syndrome (BSS). These genes are unique in the genome and encode for glycoprotein subunits of the GPIb-IX complex. Quantitative or qualitative deficiency in this complex is often associated with BSS. Here, we report the novel variant of BSS in which Ser23 of GPIbβ is substituted by a Stop codon causing a premature termination of translation, recently described in one family. This genetic defect is revealed in three unrelated BSS patients. The pedigree was determined for two families (F1 and F2) and revealed the homozygosity of the mutation in the two patients and its heterozygosity in parents. In the third family, the patient DNA was heterozygote with the same Ser23 Stop mutation in addition to two missense heterozygote mutations (Asp 51 Gly) and (Ala 55 to Pro). We studied the effect of the Ser23 Stop mutation on the expression of the complex. Our findings confirm that the identified GPIbβ mutation is responsible for the BSS phenotype and hampers the GPIb-IX complex to form on the platelets' surface. Regarding the scarcity of the BSS syndrome, the occurrence of the same mutation in three unrelated families would suggest a BSS founder mutation in Tunisia.Annals of Hematology 06/2009; 89(1):75-81. · 2.62 Impact Factor -
Article: Bernard–Soulier syndrome: novel nonsense mutation in GPIbβ gene affecting GPIb–IX complex expression
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ABSTRACT: Bernard–Soulier syndrome (BSS) is a rare autosomal recessive genetic disorder characterized by thrombocytopenia, circulating giant platelets, and prolonged bleeding time. BSS is explained by a defect in primary hemostasis owing to quantitative or qualitative defect in the GPIb–IX–V complex, composed of four subunits: GPIbα, GPIbβ, GPIX, and GPV. In this study, we report a novel GPIbβ defect in a Tunisian family, in which Serine 23 is substituted by a Stop codon causing a premature termination of translation. This defect was homozygous in the BSS patient and heterozygote in both the parents and sisters of the patient. We studied the effect of this mutation on the expression of the GPIb–IX complex by western blot, flow cytometry, and confocal microscopy: GPIbα and GPIX were absent on the surface of platelets, whereas they were present in the cytoplasm. These results led to conclude that the novel Ser 23 Stop mutation in GPIbβ is responsible of BSS in the studied family and hampers the complex to form on the platelets surface.Annals of Hematology 04/2009; 88(5):465-472. · 2.62 Impact Factor
