Olfa Messaoud
Pasteur Institute
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Featured researches published by Olfa Messaoud.
International Journal of Dermatology | 2010
Olfa Messaoud; Mariem Ben Rekaya; Wafa Cherif; Faten Talmoudi; Hammouda Boussen; Incaf Mokhtar; Samir Boubaker; Ahlem Amouri; Sonia Abdelhak; M. Zghal
Background Xeroderma Pigmentosum (XP) is a rare autosomal recessive disorder characterized by cutaneous and ocular alterations. Eight genes, Xeroderma Pigmentosum group A (XPA) to Xeroderma Pigmentosum group G (XPG) and Xeroderma Pigmentosum group V (XPV), are known to be responsible for the disease and products of these genes are involved in the repair of deoxyribonucleic acid (DNA) lesions generated by UV radiation. Several XP patients suffer from neurological defects, found in the XPA (the most common form), D and G groups. The aim of this study was to investigate the mutational spectrum of XPA in Tunisia, in order to propose a simple tool for molecular diagnosis.
British Journal of Dermatology | 2009
Olfa Messaoud; M. Ben Rekaya; Rym Kefi; S. Chebel; A. Boughammoura-Bouatay; H. Bel Hadj Ali; N. Gouider-Khouja; Jameleddine Zili; M. Frih-Ayed; Incaf Mokhtar; Sonia Abdelhak; M. Zghal
Xeroderma pigmentosum (XP) is a rare genodermatosis predisposing to skin cancers. The disease is classified into eight groups. Among them, XP group A (XP‐A) is characterized by the presence of neurological abnormalities in addition to cutaneous symptoms. In the present study, we report a particular family with XP‐A in which some members showed an atypical clinical presentation, i.e. unexplained neurological abnormalities with discrete skin manifestations. Molecular investigation allowed identification of a novel XPA mutation and complete phenotype–genotype correlation for this new phenotypic expression of XP‐A.
Gene | 2014
Khalda Amr; Olfa Messaoud; Mohamad El Darouti; Sonia Abdelhak; Ghada El-Kamah
Xeroderma pigmentosum (XP) is a rare autosomal recessive hereditary disease characterized by hyperphotosensitivity, DNA repair defects and a predisposition to skin cancers. The most frequently occurring type worldwide is the XP group A (XPA). There is a close relationship between the clinical features that ranged from severe to mild form and the mutational site in XPA gene. The aim of this study is to carry out the mutational analysis in Egyptian patients with XP-A. This study was carried out on four unrelated Egyptian XP-A families. Clinical features were examined and direct sequencing of the coding region of XPA gene was performed in patients and their parents. Direct sequencing of the whole coding region of the XPA gene revealed the identification of two homozygous nonsense mutations: (c.553C >T; p.(Gln185)) and (c.331G>T; p.(Glu111)), which create premature, stop codon and a homodeletion (c.374delC: p.Thr125Ilefs 15) that leads to frameshift and premature translation termination. We report the identification of one novel XPA gene mutation and two known mutations in four unrelated Egyptian families with Xermoderma pigmentosum. All explored patients presented severe neurological abnormalities and have mutations located in the DNA binding domain. This report gives insight on the mutation spectrum of XP-A in Egypt. This would provide a valuable tool for early diagnosis of this severe disease.
Journal of Genetics | 2011
Mariem Ben Rekaya; Olfa Messaoud; A. Mebazaa; Olfa Riahi; Hela Azaiez; Rim Kefi; M. Zghal; Samir Boubaker; Ahlem Amouri; Amel Ben Osman-Dhahri; Sonia Abdelhak; M. Mokni
XP occurs at higher frequency in Tunisia (1:10,000) than in Japan (1:22,000) (Hirai et al. 2006) and the United States (1 per million) (Kleijer et al. 2008). XP-V cells are unable to synthesize intact daughter DNA strands on UV-irradiated templates resulting from an inability to carry out translesion synthesis (Lehmann et al. 1975; Masutani et al. 1999). Approximately 20% of XP patients belong to XP-V complementation group (Gratchev et al. 2003). In Tunisia, XP is classified into three clinical forms: severe, intermediate with or without neurological abnormalities, and moderate (Zghal et al. 2006). Previous molecular investigation showed homogeneity of mutational spectrum in XPA and XPC genes (Ben Rekaya et al. 2009; Messaoud et al. 2010a,b). The moderate clinical form of XP is characterized by mild dermatological manifestations, no neurological abnormalities and late onset of skin cancers. The median age of onset is 4 years. Mild skin symptoms and late onset of skin tumours have been already described in XP-V (Tanioka et al. 2007), XP-F (Matsumura et al. 1998) and XP-E patients (Rapic-Otrin et al. 2003). Post-UV cell survival in the presence or absence of caffeine (Itoh et al. 2000), unscheduled DNA synthesis (UDS) and detection of polymerase eta employing Western blot (Tanioka et al. 2007) cannot define exactly the molecular defects are in the polymerase eta. These laboratory assays are used to find out the UV sensitivities of the patients’ cells and the DNA repair status of their cells as
Gene | 2013
Yosra Bouyacoub; Hela Zribi; H. Azzouz; Fehmi Nasrallah; Rim Ben Abdelaziz; Monia Kacem; Ben Rekaya; Olfa Messaoud; Lilia Romdhane; Cherine Charfeddine; Mustapha Bouziri; Sonia Bouziri; Neji Tebib; M. Mokni; Naziha Kaabachi; Samir Boubaker; Sonia Abdelhak
Tyrosinemia type II, also designated as oculocutaneous tyrosinemia or Richner-Hanhart syndrome (RHS), is a very rare autosomal recessive disorder. In the present study, we report clinical features and molecular genetic investigation of the tyrosine aminotransferase (TAT) gene in two young patients, both born to consanguineous unions between first-degree cousins. These two unrelated families originated from Northern and Southern Tunisia. The clinical diagnosis was based on the observation of several complications related to Richner-Hanhart syndrome: recurrent eye redness, tearing and burning pain, photophobia, bilateral pseudodendritic keratitis, an erythematous and painful focal palmo-plantar hyperkeratosis and a mild delay of mental development. The diagnosis was confirmed by biochemical analysis. Sequencing of the TAT gene revealed the presence of a previously reported missense mutation (c.452G>A, p.Cys151Tyr) in a Tunisian family, and a novel G duplication (c.869dupG, p.Trp291Leufs 6). Early diagnosis of RHS and protein-restricted diet are crucial to reduce the risk and the severity of long-term complications of hypertyrosinemia such as intellectual disability.
BioMed Research International | 2014
Mariem Ben Rekaya; Nadia Laroussi; Olfa Messaoud; Mariem Jones; M. Jerbi; Chokri Naouali; Yosra Bouyacoub; Mariem Chargui; Rym Kefi; B. Fazaa; Mohamed Samir Boubaker; Hamouda Boussen; M. Mokni; Sonia Abdelhak; Mohamed Zghal; Aida Khaled; H. Yacoub-Youssef
Xeroderma pigmentosum Variant (XP-V) form is characterized by a late onset of skin symptoms. Our aim is the clinical and genetic investigations of XP-V Tunisian patients in order to develop a simple tool for early diagnosis. We investigated 16 suspected XP patients belonging to ten consanguineous families. Analysis of the POLH gene was performed by linkage analysis, long range PCR, and sequencing. Genetic analysis showed linkage to the POLH gene with a founder haplotype in all affected patients. Long range PCR of exon 9 to exon 11 showed a 3926 bp deletion compared to control individuals. Sequence analysis demonstrates that this deletion has occurred between two Alu-Sq2 repetitive sequences in the same orientation, respectively, in introns 9 and 10. We suggest that this mutation POLH NG_009252.1: g.36847_40771del3925 is caused by an equal crossover event that occurred between two homologous chromosomes at meiosis. These results allowed us to develop a simple test based on a simple PCR in order to screen suspected XP-V patients. In Tunisia, the prevalence of XP-V group seems to be underestimated and clinical diagnosis is usually later. Cascade screening of this founder mutation by PCR in regions with high frequency of XP provides a rapid and cost-effective tool for early diagnosis of XP-V in Tunisia and North Africa.
American Journal of Human Biology | 2016
Nizar Ben Halim; Sana Hsouna; Khaled Lasram; Insaf Rejeb; Asma Walha; Faten Talmoudi; Habib Messai; Ahlem Sabrine Ben Brick; Houyem Ouragini; Wafa Cherif; Majdi Nagara; Faten Ben Rhouma; Ibtissem Chouchene; Farah Ouechtati; Yosra Bouyacoub; Mariem Ben Rekaya; Olfa Messaoud; Slim Ben Ammar; Leila El Matri; Neji Tebib; Marie Francoise Ben Dridi; M. Mokni; Ahlem Amouri; Rym Kefi; Sonia Abdelhak
Consanguinity is common in Tunisia. However, little information exists on its impact on recessive disorders. In this study, we evaluate the impact of consanguineous marriages on the occurrence of some specific autosomal recessive disorders and consider how other factors, such as population substructure and mutation frequency, may be of equal importance in disease prevalence.
Human Heredity | 2014
Lilia Romdhane; Nizar Ben Halim; Insaf Rejeb; Rym Kefi; Yosra Bouyacoub; Mariem Ben Rekaya; Habib Messai; Olfa Messaoud; Zied Riahi; Crystel Bonnet; Faten Ben Rhouma; Majdi Nagara; Christine Petit; Ken McElreavey; Giovanni Romeo; Sonia Abdelhak
Located at the cross-road between Europe and Africa, Tunisia is a North African country of 11 million inhabitants. Throughout its history, it has been invaded by different ethnic groups. These historical events, and consanguinity, have impacted on the spectrum and frequency of genetic diseases in Tunisia. Investigations of Tunisian families have significantly contributed to elucidation of the genetic bases of rare disorders, providing an invaluable resource of cases due to particular familial structures (large family size, consanguinity and share of common ancestors). In the present study, we report on and review different aspects of consanguinity in the Tunisian population as a case study, representing several features common to neighboring or historically related countries in North Africa and the Middle East. Despite the educational, demographic and behavioral changes that have taken place during the last four decades, familial and geographical endogamy still exist at high frequencies, especially in rural areas. The health implications of consanguinity in Tunisian families include an increased risk of the expression of autosomal recessive diseases and particular phenotypic expressions. With new sequencing technologies, the investigation of consanguineous populations provides a unique opportunity to better evaluate the impact of consanguinity on the genome dynamic and on health, in addition to a better understanding of the genetic bases of diseases.
Hormone Research in Paediatrics | 2014
Lamia Cherif Ben Abdallah; Y. Lakhoua; Majdi Nagara; K. Khiari; Sahar Elouej; Olfa Messaoud; Yosra Bouyacoub; Lilia Romdhane; Z. Turki; Sonia Abdelhak; Nejib Ben Abdallah
Background/Aims: The coexistence of triple A syndrome (AAAS) and congenital hypogonadotropic hypogonadism (CHH) has so far not been reported in the literature. This study aimed to characterize at the clinical and genetic level one patient presenting an association of AAAS and CHH in order to identify causal mutations. Methods: Clinical and endocrinal investigations were performed and followed by mutational screening of candidate genes. Results: At the age of 18, the patient presented sexual infantilism, a micropenis and gynecomastia. No mutation was revealed in GnRHR, TACR3/TAC3, PROK2/PROKR2 and PROP1 genes, except a homozygous intronic variation (c.244 + 128C>T; dbSNP: rs350129) in the KISS1R gene, which is likely nondeleterious. A homozygous splice-donor site mutation (IVS14 + 1G>A) was found in the AAAS gene. This mutation, responsible for AAAS, is a founder mutation in North Africa. Conclusion: This is the first report on a Tunisian patient with the coexistence of AAAS and CHH. The diagnosis of CHH should be taken in consideration in patients with Allgrove syndrome and who carry the IVS14 + 1G>A mutation as this might challenge appropriate genetic counseling.
BioMed Research International | 2013
Mariem Ben Rekaya; M. Jerbi; Olfa Messaoud; Ahlem Sabrine Ben Brick; Mohamed Zghal; Chiraz Mbarek; Ashraf Chadli-Debbiche; M. Jones; M. Mokni; Hamouda Boussen; Mohamed Samir Boubaker; B. Fazaa; H. Yacoub-Youssef; Sonia Abdelhak
Xeroderma Pigmentosum (XP) is a rare recessive autosomal cancer prone disease, characterized by UV hypersensitivity and early appearance of cutaneous and ocular malignancies. We investigated four unrelated patients suspected to be XP-C. To confirm linkage to XPC gene, genotyping and direct sequencing of XPC gene were performed. Pathogenic effect of novel mutations was confirmed by reverse Transciptase PCR. Mutation screening revealed the presence of two novel mutations g.18246G>A and g.18810G>T in the XPC gene (NG_011763.1). The first is present in one patient XP50NEF, but the second is present in three unrelated patients (XP16KEB, XP28SFA, and XP45GB). These 3 patients are from three different cities of Southern Tunisia and bear the same haplotype, suggesting a founder effect. Reverse Transciptase PCR revealed the absence of the XPC mRNA. In Tunisia, as observed in an other severe genodermatosis, the mutational spectrum of XP-C group seems to be homogeneous with some clusters of heterogeneity that should be taken into account to improve molecular diagnosis of this disease.