153 results on '"Houmeida A"'
Search Results
2. Genetic variation of TLR3 gene is associated with the outcome of hepatitis b infection in mauritanian patients: case control study
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Soumbara, Tetou, Bonnet, Crystel, Hamed, Cheikh Tijani, Veten, Fatimetou, Hemeyine, Mohamed, Fall-Malick, F-Zahra, El Yezid, Mohamed Mahmoud, Diallo, Aichetou, Mounah, Moustapha Mouhamedou, and Houmeida, Ahmed
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- 2024
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3. Genetic variation of TLR3 gene is associated with the outcome of hepatitis b infection in mauritanian patients: case control study
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Tetou Soumbara, Crystel Bonnet, Cheikh Tijani Hamed, Fatimetou Veten, Mohamed Hemeyine, F-Zahra Fall-Malick, Mohamed Mahmoud El Yezid, Aichetou Diallo, Moustapha Mouhamedou Mounah, and Ahmed Houmeida
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Chronic hepatitis B virus ,Single-nucleotide polymorphism ,TLR3 ,TLR4 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Toll-Like receptors (TLRs) play an important role in the immune response during hepatitis B virus (HBV) infection. In this study, we evaluated the association between two SNP variants (TLR3 rs3775290 and TLR4 rs4986790) and susceptibility to chronic HBV infection in Mauritania. Subjects and methods : A total of 188 subjects were recruited for this study: 102 chronically infected patients and 86 individuals with spontaneously resolved HBV infection who were considered controls. Targeted PCR products were sequenced using Sanger sequencing. Results We found that TLR3 rs3775290 was significantly more frequent in patients with chronic HBV than in the control population (p = 0.03). However, no association was found between the TLR4 rs3775290 polymorphism and chronic infection. Conclusion Our results suggest that the TLR3 rs3775290 polymorphism may be a risk factor for susceptibility to chronic HBV infection in the Mauritanian population.
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- 2024
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4. Identification a novel pathogenic LRTOMT mutation in Mauritanian families with nonsyndromic deafness
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Salame, Malak, Bonnet, Crystel, Moctar, Ely Cheikh Mohamed, Brahim, Selma Mohamed, Dedy, Abdallahi, Vetah, Ledour Abdel, Veten, Fatimetou, Hamed, Cheikh Tijani, Petit, Christine, and Houmeida, Ahmed
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- 2023
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5. General Oncology Care in Mauritania
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Mohamed Brahim, Selma, Zein, Ekhtelebenina, Houmeida, Ahmed, Tolba, Ahmedou, Al-Shamsi, Humaid O., editor, Abu-Gheida, Ibrahim H., editor, Iqbal, Faryal, editor, and Al-Awadhi, Aydah, editor
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- 2022
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6. Screening of BRCA1/2 variants in Mauritanian breast cancer patients
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Selma Mohamed Brahim, Ekht Elbenina Zein, Crystel Bonnet, Cheikh Tijani Hamed, Malak Salame, Mohamed Vall Zein, Meriem Khyatti, Ahmedou Tolba, and Ahmed Houmeida
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Breast cancer (BC) ,BRCA1/2 ,Variant ,Women ,Mauritania ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background and study aim Carrying a pathogenic BRCA1/2 variant increases greatly young women’s risk of developing breast cancer (BC). This study aimed to provide the first genetic data on BC in Mauritania. Methods Using NGS based screening; we searched for BRCA1/2 variants in DNA samples from 137 patients diagnosed for hereditary BC. Results We identified 16 pathogenic or likely pathogenic (PV) variants carried by 38 patients. Two predominant BRCA1 PV variants were found: c.815_824dup and c.4986 + 6 T > C in 13 and 7 patients, respectively. Interestingly, three novels BRCA1/2 predicted pathogenic variants have also been detected. Notably, no specific distribution of BRCA1/2 variants was observed regarding triple negative breast cancer (TNBC) or patient gender status. Conclusions In this first genetic profiling of BC in Mauritania, we identified a substantial number of BRCA1/2 pathogenic variants. This finding could be important in the future diagnosis and prevention policy of hereditary BC in Mauritania.
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- 2022
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7. Genomic Evidence of Multiple Introductions of SARS-CoV-2 in Mauritania
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Abdelmalick Abdelmalick, Sofia Sehli, Abdellah Idrissi Azami, Nihal Habib, Najib Al Idrissi, Lahcen Belyamani, Ahmed Houmeida, and Hassan Ghazal
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Biology (General) ,QH301-705.5 - Abstract
The rapid and global spread of the novel coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has raised serious public health concerns, including in Mauritania. We sequenced and analyzed the entire genome of 13 SARS-CoV-2 virus strains isolated from polymerase chain reaction (PCR)-positive symptomatic patients sampled from March 3 to May 31, 2021 to better understand SARS-CoV-2 introduction, propagation, and evolution in Mauritania. A phylogenetic tree using available data from the EpiCoV GISAID database and a variant network with non-Mauritanian sequences were constructed. Variant analysis of the 13 Mauritanian SARS-CoV-2 genome sequences indicated an average mutational percentage of 0.39, which is similar to that in other countries. Phylogenetic analysis revealed multiple spatiotemporal introductions, mainly from Europe (France, Belgium) and Africa (Senegal, Côte d’Ivoire), which also provided evidence of early community transmission. A total of 2 unique mutations, namely, NSP6_Q208K and NSP15_S273T, were detected in the NSP6 and NSP15 genes, respectively, confirming the aforementioned introduction of SARS-CoV-2 in Mauritania. These findings highlight the relevance of continuous genomic monitoring strategies for understanding virus transmission dynamics and acquiring knowledge to address forthcoming sources of infection in Africa.
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- 2023
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8. Screening of BRCA1/2 variants in Mauritanian breast cancer patients
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Brahim, Selma Mohamed, Zein, Ekht Elbenina, Bonnet, Crystel, Hamed, Cheikh Tijani, Salame, Malak, Zein, Mohamed Vall, Khyatti, Meriem, Tolba, Ahmedou, and Houmeida, Ahmed
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- 2022
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9. The Genetic Epidemiology of Orphan Diseases in North Africa
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Romdhane, Lilia, primary, Messaoud, Olfa, additional, Kefi, Rym, additional, Tiar, Afaf, additional, Amouri, Ahlem, additional, Mokni, Mourad, additional, Tebib, Neji, additional, Zghal, Mohamed, additional, Barakat, Abdelhamid, additional, Houmeida, Ahmed, additional, Bozguiya, Mariem, additional, Othman, Mohamed, additional, El-Kamah, Ghada, additional, and Abdelhak, Sonia, additional
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- 2019
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10. HLA class I (-A, -B, -C) and class II (-DR, -DQ) polymorphism in the Mauritanian population
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Cheikh Tijani Hamed, Ghlana Meiloud, Fatimetou Veten, Mouna Hadrami, Sidi M. Ghaber, Ely C. Boussaty, Norddine Habti, and Ahmed Houmeida
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HLA ,Population ,Mauritania ,Pcr-ssp ,Internal medicine ,RC31-1245 ,Genetics ,QH426-470 - Abstract
Abstract Background HLA antigens have been widely studied for their role in transplantation biology, human diseases and population diversity. The aim of this study was to provide the first profile of HLA class I and class II alleles in the Mauritanian population. Methods HLA typing was carried in 93 healthy Mauritanian blood donors, using single specific primer amplification (PCR-SSP). Results Occurrences of the main HLA class I (-A, -B, -C) and class II (-DR, -DQ) antigens in the general population showed that out of the 17 HLA-A allele groups detected, five main HLA-A allele groups: A*02 (18.42%), A*01 (14.04%), A*23 (14.04%), A*30 (13.16%) and A*29 (12.28%) were the most common identified along other 12 relatively minor allele groups. Twenty three allele groups were observed in the locus B of which B*07 (13.46%) was the most prevalent followed by B*15, B*35, B*08 and B*27 all, with a frequency between 7 to 8%. Three prevalent HLA-C allele groups (C*02: 35.09%, C*07: 20.19% and C*06: 13.6%) were detected. The main HLA class II observed allele groups were: DRB1*13 (27.42%), DRB1*03 (24.73%), DRB1*11 (13.98%), DQB1*03 (36.03%), DQB1*02 (22.06%) and DQB1*05 (18.8%). Except for few haplotype in class I (A*02-B*07: 4.45%, A*02-C02: 10%, A*23-C*02: 8.8%, B*07-C*02: 8.8%, B*15-C*02: 8.8%) and in class II (DRB1*13-DQB1*06: 11.94%, DRB1*03-DQB1*02:11.19% and DRB1*03-DQB1*03: 10.45%), the majority of locus combination were in the range of 2–3%. A single predominant haplotype C*02-DRB1*03 (16.67%) was found. Conclusions These results, in agreement with previous data using different tissues markers, underlined the ethnic heterogeneity of the Mauritanian population.
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- 2018
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11. Epidemiological and clinicopathological features of breast cancer in Mauritania = Características epidemiológicas y clinicopatológicas del cáncer de mama en Mauritania
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Mohamed Brahim, Selma, Tijani Hamed,Cheikh, Zein, Ekht Elbenina, Salame, Malak, Veten, Fatimetou, Vall Zein, Mohamed, Khyatti, Meriem, Houmeida, Ahmed, Tolba, Ahmedou, Mohamed Brahim, Selma, Tijani Hamed,Cheikh, Zein, Ekht Elbenina, Salame, Malak, Veten, Fatimetou, Vall Zein, Mohamed, Khyatti, Meriem, Houmeida, Ahmed, and Tolba, Ahmedou
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[eng] Background: Breast cancer is the leading cause of death in African women. The aim of this cross –sectional study was to assess the incidence, clinic-pathological characteristics, risk factors and outcome of breast cancer in Mauritania. Methods: Demographic and clinic pathological features of breast cancer were gathered from 11174 patient files of all cancer types referred to the Centre National d’Oncologie (CNO) between January 2009 and December 2020. Results: Breast cancer was the most common type of cancer identified in women (30.7%). The disease incidence increased from 69 in 2009 to 209 in 2020 with a mean age of 49 year sat cancer detection. Grade 3 tumor was diagnosed in 31.8% patients. Stage 3 and metastasic stage were found respectively in 44.9 % and 22.6% of screened women. 40.4% of cancer patients with satisfactory immunohistochemical data were triple negative breast cancer (TNBC) but no significant variation was found in these features between TNBC and non TNBC groups. A 3-year survival rate of 63% was observed. Conclusions: These results support the already published studies on the likely genetic basis of breast cancer in our population., [spa] Antecedentes: El cáncer de mama es la principal causa de muerte en las mujeres africanas. El objetivo de este estudio transversal fue evaluar la incidencia, las características clínico-patológicas, los factores de riesgo y el resultado del cáncer de mama en Mauritania. Métodos: Las características demográficas y clínico-patológicas del cáncer de mama se recogieron de 11174 expedientes de pacientes de todos los tipos de cáncer remitidos al Centre National d’Oncologie (CNO) entre enero de 2009 y diciembre de 2020. Resultados: El cáncer de mama fue el tipo de cáncer más común identificado en las mujeres (30,7%). La incidencia de la enfermedad aumentó de 69 en 2009 a 209 en 2020 con una edad media de 49 años de detección del cáncer. Se diagnosticó un tumor de grado 3 en el 31,8% de las pacientes. El estadio 3 y el estadio metastásico se encontraron, respectivamente, en el 44,9% y el 22,6% de las mujeres examinadas. El 40,4% de las pacientes con cáncer con datos inmunohistoquímicos satisfactorios eran cáncer de mama triple negativo (TNBC), pero no se encontraron variaciones significativas en estas características entre los grupos TNBC y no TNBC. Se observó una tasa de supervivencia a 3 años del 63%. Conclusiones: Estos resultados apoyan los estudios ya publicados sobre la probable base genética del cáncer de mama en nuestra población.
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- 2023
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12. Identification a novel pathogenic LRTOMT mutation in Mauritanian families with nonsyndromic deafness
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Malak Salame, Crystel Bonnet, Ely Cheikh Mohamed Moctar, Selma Mohamed Brahim, Abdallahi Dedy, Ledour Abdel Vetah, Fatimetou Veten, Cheikh Tijani Hamed, Christine Petit, Ahmed Houmeida, Université de Nouakchott Al-Aasriya (UNA), Institut de l'Audition [Paris] (IDA), Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), University of California [San Diego] (UC San Diego), University of California (UC), Centre National d'Oncologie [Mauritanie] (CNO), Centre Hospitalier National [Nouakchott, Mauritania], Centre National d'Hépato-Virologie [Mauritanie], Collège de France (CdF (institution)), and This work was supported by Fondation pour l’Audition (FPA-IDA05) and the ANRSI-Mauritania.
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LRTOMT ,Otorhinolaryngology ,[SDV]Life Sciences [q-bio] ,Mutation ,Mauritania ,General Medicine ,Deafness ,SNHI - Abstract
International audience; PurposeAlthough recessive mutations in GJB2 are the common genetic etiology of sensorineural hearing impairment (SNHI), variants in LRTOMT gene were also identified, mostly in Middle East and North African populations.MethodsUsing Sanger sequencing we screened the exon 7 of LRTOMT in a cohort of 128 unrelated Mauritanian children with congenital deafness.ResultsOnly one biallelic missense mutation, predicted as pathogenic (c.179 T > C;p.Leu60Pro) was found at homozygous state in four families. This variant, not reported before, showed a deleterious effect by SIFT (score: 0.01) and a disease-causing effect by Mutation Taster (prob: 1). Exploration of the encoded protein 3D structure revealed a disruption from an organized α helix (in the normal protein structure) into a random conformation. Early fitting of a cochlear implant seemed to improve the audition ability of the mutation carrier.ConclusionFurther screening using a panel of deafness genes may expose other variants underlying hearing impairment in our population.
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- 2023
13. Splice-altering variant of PJVKgene in a Mauritanian family with non-syndromic hearing impairment
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Salame, Malak, Bonnet, Crystel, Singh-Estivalet, Amrit, Brahim, Selma Mohamed, Roux, Solene, Boussaty, Ely Cheikh, Hadrami, Mouna, Hamed, Cheikh Tijani, Sidi, Abdellahi M’hamed, Veten, Fatimetou, Petit, Christine, and Houmeida, Ahmed
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PJVKgene was recently shown to create hypervulnerability to sound in humans and was the first human gene implicated in non-syndromic hearing impairment due to neural defect. Targeted next-generation sequencing of over 150 known deafness genes was performed in the proband. Sanger sequencing was used to validate the PJVKvariant and confirm familial segregation of the disease. A minigene-based assay has been performed to assess the impact of the variant on splicing. We identified a novel c.550-6A > G acceptor splice-site variant in the PJVKgene in the homozygous state in a Mauritanian child with severe to profound congenital deafness. The substitution was located in intron 4. The effect of the variation was demonstrated by a minigene assay which showed that the variation, an insertion of an additional 5 bp, created a new splice site resulting in the appearance of a premature stop codon (p.Phe184Tyrfs*26) and likely a truncated protein. This result constitutes a new splice-site variant report in the PJVKgene leading to DFNB59 type associated with autosomal recessive non-syndromic hearing impairment (ARNSHI).
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- 2024
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14. Etiology and associated GJB2 mutations in Mauritanian children with non-syndromic hearing loss
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Moctar, Ely Cheikh Mohamed, Riahi, Zied, El Hachmi, Hala, Veten, Fatimetou, Meiloud, Ghlana, Bonnet, Christine, Abdelhak, Sonia, Errami, Mohammed, and Houmeida, Ahmed
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- 2016
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15. E23K variant in KCNJ11 gene is associated with susceptibility to type 2 diabetes in the Mauritanian population
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Abdelhamid, Isselmou, Lasram, Khaled, Meiloud, Ghlana, Ben Halim, Nizar, Kefi, Rym, Samb, Abdoulaye, Abdelhak, Sonia, and Houmeida, Ahmed
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- 2014
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16. Type 2 diabetes in Mauritania: Prevalence of the undiagnosed diabetes, influence of family history and maternal effect
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Meiloud, Ghlana, Arfa, Imen, Kefi, Rym, Abdelhamid, Isselmou, Veten, Fatimetou, Lasram, Khaled, Ben Halim, Nizar, Sidi Mhamed, Abdallahi, Samb, Abdoulaye, Abdelhak, Sonia, and Houmeida, Ahmed Ould
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- 2013
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17. General Oncology Care in Mauritania
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Selma Mohamed Brahim, Ekhtelebenina Zein, Ahmed Houmeida, and Ahmedou Tolba
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As in most African countries, cancer is rapidly becoming a public health problem in Mauritania due to the lack of financial resources, scarcity of skilled health workers, and prevalence of inherent risk factors. Efforts are undertaken by the government to ease the burden of this disease on the local population. In this chapter, we present the history and milestones of oncology in Mauritania, the attempts by the state to fight cancer progression and the prospect of these actions.
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- 2022
18. Epidemiological and Clinicopathological Features of Breast Cancer in Mauritania
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Fatimetou Veten, Selma Mohamed Brahim, EkhtElbenina Zein, Ahmed Houmeida, Ahmedou Tolba, Meriem Khyatti, Mohamed Vall Zein, Malak Salame, and Cheikh Tijani Hamed
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Oncology ,medicine.medical_specialty ,Breast cancer ,business.industry ,Internal medicine ,Epidemiology ,medicine ,Clinicopathological features ,medicine.disease ,business - Abstract
Background Breast cancer is the leading cause of death in African women. The aim of this retrospective study was to assess the incidence, clinico-pathological characteristics, risk factors and outcome of breast cancer in Mauritania.Methods Demographic and clinico‑pathological features of breast cancer were gathered from 11174 patient files of all cancer types referred to the Centre National d’Oncologie (CNO) between January 2009 and December 2020.ResultsBreast cancer was the most common type of cancer identified in women (30.7%). The diseaseincidence increased from 69 in 2009 to 209 in 2020 with a mean age of 49 year sat cancer detection. Grade 3 tumor was diagnosed in 31.8% patients. Stage 3 and metastasic stage were found respectively in 44.9 % and 22.6% of screened women. 40.4% of cancer patients with satisfactory immunohistochemical data were triple negative breast cancer (TNBC) but no significant variation was found in these features between TNBC and non TNBC groups. A 3‐year survival rate of 63% was observed.ConclusionsThese results support the already published studies on the likely genetic basis of breast cancer in our population.
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- 2021
19. Studies of the Interaction between Titin and Myosin
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Houmeida, A., Holt, J., Tskhovrebova, L., and Trinick, J.
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- 1995
20. mtDNA 16184–16193 poly-C tract does not predispose to type 2 diabetes in the Mauritanian population
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Meiloud, G., Kefi, R., Abdelhamid, I., Lasram, K., Samb, A., Abdelhak, S., and Houmeida, Ahmed O.
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- 2013
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21. Epidemiological and Clinicopathological Features of Breast Cancer in Mauritania
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BRAHIM, Selma MOHAMED, primary, HAMED, Cheikh Tijani, additional, ZEIN, EkhtElbenina, additional, SALAME, Malak, additional, VETEN, Fatimetou, additional, ZEIN, Mohamed Vall, additional, KHYATTI, Meriem, additional, HOUMEIDA, Ahmed, additional, and TOLBA, Ahmedou, additional
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- 2021
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22. Characteristics of Helicobacter pylori strains isolated from Mauritanian patients
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Nabil Gastli, Ahmed Mohamed Amar, Annick Billoët, Catherine Dauga, Josette Raymond, Hachem Demine Moctar Nech, Ghislaine Collobert, Mohamed val Mohamed Abdellahi, Fatimetou Khiddi, El Heiba Mohamed Vadel, Ahmed Houmeida, Mohamed Abdallah Horma, Epidemiology and Diversity of Microorganisms [Nouakchott, Mauritania], Chiva Clinic [Nouakchott, Mauritania], Service de Bactériologie [CHU Cochin, AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Cochin [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre Hospitalier National [Nouakchott, Mauritania], AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre), Département de Biologie Computationnelle - Department of Computational Biology, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)
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Male ,Disease ,[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy ,Gastroenterology ,0302 clinical medicine ,Polymorphism (computer science) ,Clarithromycin ,Child ,Aged, 80 and over ,2. Zero hunger ,education.field_of_study ,Mauritania ,General Medicine ,Middle Aged ,3. Good health ,Infectious Diseases ,PCR ,030220 oncology & carcinogenesis ,Female ,030211 gastroenterology & hepatology ,medicine.drug ,Adult ,medicine.medical_specialty ,Adolescent ,Virulence Factors ,Population ,Virulence ,cagA gene ,Biology ,Helicobacter Infections ,Young Adult ,03 medical and health sciences ,Bacterial Proteins ,Internal medicine ,Drug Resistance, Bacterial ,medicine ,Humans ,CagA ,education ,Aged ,Antigens, Bacterial ,Helicobacter pylori ,Cancer ,medicine.disease ,biology.organism_classification ,bacterial infections and mycoses ,digestive system diseases ,EPIYA motif - Abstract
BACKGROUND Helicobacter pylori (H pylori) is responsible for various diseases including cancer It co-evolved with humans, and human migrations shaped the expansion and the diversity of strains around the world. The risk of developing a disease depends on virulence factors, mainly the cytotoxin-associated gene A protein (CagA). The aim of this study was to determine the cagA status in H pylori strains from Mauritanian patients and to search for a relationship with endoscopic and histologic findings. MATERIAL AND METHODS H pylori was searched in gastric biopsies taken during endoscopy in patients with gastro-duodenal symptoms. RT-PCR was used for the diagnosis and resistance to clarithromycin. The cagA status was determined with PCR and the EPIYA-cagA polymorphism with sequencing. RESULTS At all, 76/78 (97.4%) biopsies were positive. The rate of clarithromycin resistance was 4/76 (5.26%) due to the A2143G mutation, with a mixed population in 2 cases. The cagA gene was present in 23/76 (30.26%) biopsies, and the EPIYA motif was ABC in 21 (91.3%). High bacterial load and inflammation were significantly associated with cagA-positive status (P
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- 2020
23. A novel missense mutation of GJA8 causes congenital cataract in a large Mauritanian family
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Isabelle Audo, Christel Condroyer, Crystel Bonnet, Med Ahmed Sidi Ahmed, Mouna Hadrami, Christina Zeitz, Ahmed Houmeida, Sidi Cheikh, Mohamed Biya, Christine Petit, Panfeng Wang, Qingjiong Zhang, Fatimetou Veten, Université des Sciences, de Technologies et de Médecine (USTM), Sorbonne Université - Faculté de Médecine (SU FM), Sorbonne Université (SU), Institut de la Vision, Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sun Yat-Sen University [Guangzhou] (SYSU), University College of London [London] (UCL), Institut Pasteur [Paris] (IP), Collège de France - Chaire Génétique et physiologie cellulaire, Collège de France (CdF (institution)), This work was supported by the Tunisian Ministry of Public Health, the Ministry of Higher Education and Scientific Research (LR11IPT05), the E.C. Grant agreement N° 295097 for FP7 project GM‐NCD‐Inco (www.genomedika.org). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript., We thank the patient and his family for their collaboration. We are grateful to the technical staff at Armand Trousseau Hospital in Paris for their assistance, European Project: 295097,EC:FP7:INCO,FP7-INCO-2011-6,GM_NCD_IN_CO(2011), Gestionnaire, Hal Sorbonne Université, Reinforcing IPT capacities in Genomic Medicine, Non Communicable Diseases Investigation and international cooperation - GM_NCD_IN_CO - - EC:FP7:INCO2011-12-01 - 2014-11-30 - 295097 - VALID, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Pasteur [Paris], and Chaire Génétique et physiologie cellulaire
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Pediatrics ,medicine.medical_specialty ,Connexin 50 ,[SDV.GEN.GH] Life Sciences [q-bio]/Genetics/Human genetics ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Missense mutation ,[SDV.MHEP.OS]Life Sciences [q-bio]/Human health and pathology/Sensory Organs ,business.industry ,Mauritania ,Childhood blindness ,General Medicine ,Cataract present ,medicine.disease ,3. Good health ,GJA8 ,Ophthalmology ,[SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics ,[SDV.MHEP.OS] Life Sciences [q-bio]/Human health and pathology/Sensory Organs ,cataract ,030221 ophthalmology & optometry ,next-generation sequencing ,sense organs ,LENS OPACITY ,business ,030217 neurology & neurosurgery - Abstract
Objective of the study: Inborn lens opacity is the most frequent cause of childhood blindness. In this study, we aimed to define the presumed genetic cause of a congenital cataract present in a Mauritanian family over the last nine generations. Methods: A family history of the disease and eye examination were carried out for the family members. Next-generation sequencing using a panel of 116 cataract underlying genes was selectively conducted on the proband’s DNA. Nucleotide and amino acid changes and their impact on the phenotype were evaluated using various data analyzing software. Results: Congenital nuclear cataract, with autosomal dominant mode, was observed in the family. All patients had consequences on their vision in the first 2 years of life. Genetic screening revealed a new mutation c.166A>C (p.Thr56Pro) in GJA8, encoding the Cx50 α-connexin protein. This mutation co-segregated in all patients and was not observed in the unaffected family members and controls. The predicted secondary structure impacted by p.Thr56Pro revealed a localized disruption, in the first extra membrane loop of the wild-type sheet, which is replaced in the mutant protein by a turn then a coil. This conformational change was functionally predicted as probably damaging. Conclusion: A new mutation (c.166A>C) in GJA8 underlying a nuclear congenital cataract was identified in this study. Its segregation with the phenotype might be useful as a predicting marker of the disease.
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- 2018
24. The Genetic Epidemiology of Orphan Diseases in North Africa
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Ghada El-Kamah, Sonia Abdelhak, Mourad Mokni, Neji Tebib, Ahlem Amouri, Afaf Tiar, Lilia Romdhane, Abdelhamid Barakat, Ahmed Houmeida, Mariem Bozguiya, Mohamed Othman, Olfa Messaoud, M. Zghal, and Rym Kefi
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Geography ,Genetic epidemiology ,North africa ,Socioeconomics ,Orphan diseases - Published
- 2019
25. HLA class I (-A, -B, -C) and class II (-DR, -DQ) polymorphism in the Mauritanian population
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Ahmed Houmeida, Ely C. Boussaty, Ghlana Meiloud, Fatimetou Veten, Cheikh Tijani Hamed, Sidi M. Ghaber, Norddine Habti, and Mouna Hadrami
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0301 basic medicine ,Male ,lcsh:Internal medicine ,lcsh:QH426-470 ,Population ,Black People ,Pcr-ssp ,Locus (genetics) ,Human leukocyte antigen ,HLA-C Antigens ,Biology ,Polymorphism, Single Nucleotide ,03 medical and health sciences ,Antigen ,Gene Frequency ,Genetics ,HLA-DQ beta-Chains ,Humans ,Allele ,education ,lcsh:RC31-1245 ,Genetics (clinical) ,Alleles ,education.field_of_study ,HLA-D Antigens ,HLA-A Antigens ,Haplotype ,Mauritania ,Molecular biology ,Transplantation ,Minor allele frequency ,HLA ,Phylogeography ,lcsh:Genetics ,030104 developmental biology ,Genetics, Population ,Haplotypes ,Genetic Loci ,HLA-B Antigens ,Female ,Research Article ,HLA-DRB1 Chains - Abstract
Background HLA antigens have been widely studied for their role in transplantation biology, human diseases and population diversity. The aim of this study was to provide the first profile of HLA class I and class II alleles in the Mauritanian population. Methods HLA typing was carried in 93 healthy Mauritanian blood donors, using single specific primer amplification (PCR-SSP). Results Occurrences of the main HLA class I (-A, -B, -C) and class II (-DR, -DQ) antigens in the general population showed that out of the 17 HLA-A allele groups detected, five main HLA-A allele groups: A*02 (18.42%), A*01 (14.04%), A*23 (14.04%), A*30 (13.16%) and A*29 (12.28%) were the most common identified along other 12 relatively minor allele groups. Twenty three allele groups were observed in the locus B of which B*07 (13.46%) was the most prevalent followed by B*15, B*35, B*08 and B*27 all, with a frequency between 7 to 8%. Three prevalent HLA-C allele groups (C*02: 35.09%, C*07: 20.19% and C*06: 13.6%) were detected. The main HLA class II observed allele groups were: DRB1*13 (27.42%), DRB1*03 (24.73%), DRB1*11 (13.98%), DQB1*03 (36.03%), DQB1*02 (22.06%) and DQB1*05 (18.8%). Except for few haplotype in class I (A*02-B*07: 4.45%, A*02-C02: 10%, A*23-C*02: 8.8%, B*07-C*02: 8.8%, B*15-C*02: 8.8%) and in class II (DRB1*13-DQB1*06: 11.94%, DRB1*03-DQB1*02:11.19% and DRB1*03-DQB1*03: 10.45%), the majority of locus combination were in the range of 2–3%. A single predominant haplotype C*02-DRB1*03 (16.67%) was found. Conclusions These results, in agreement with previous data using different tissues markers, underlined the ethnic heterogeneity of the Mauritanian population.
- Published
- 2018
26. Can the passive elasticity of muscle be explained directly from the mechanics of individual titin molecules?
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Tskhovrebova, Larissa, Houmeida, Ahmed, and Trinick, John
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- 2005
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27. Frequencies and ethnic distribution of ABO and Rh(D) blood groups in Mauritania: results of first nationwide study
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Hamed, C. T., Bollahi, M. A., Abdelhamid, I., Med Mahmoud, M. A., BA, B., Ghaber, S., Habti, N., and Houmeida, A.
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- 2012
- Full Text
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28. Characteristics of Helicobacter pylori strains isolated from Mauritanian patients
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Khiddi, Fatimetou, primary, Abdellahi, Mohamed val Mohamed, additional, Horma, Mohamed Abdallah, additional, Billoet, Annick, additional, Collobert, Ghislaine, additional, Amar, Ahmed Mohamed, additional, Nech, Hachem Demine Moctar, additional, Vadel, El Heiba Mohamed, additional, Houmeida, Ahmed, additional, Raymond, Josette, additional, Dauga, Catherine, additional, and Gastli, Nabil, additional
- Published
- 2020
- Full Text
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29. Mutation profile of glaucoma candidate genes in Mauritanian families with primary congenital glaucoma
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Hadrami, Mouna, Bonnet, Crystel, Zeitz, Christina, Veten, Fatimetou, Biya, Med, Hamed, Cheikh T., Condroyer, Christel, Wang, Panfeng, Sidi, Med Mahmoud, Cheikh, Sidi, Qingjiong Zhang, Audo, Isabelle, Petit, Christine, Houmeida, Ahmed, Faculté des Sciences et Techniques [Nouakchott, Mauritania], Institut de la Vision, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM), ED 515 - Complexité du vivant, Université Pierre et Marie Curie - Paris 6 (UPMC), Sun Yat-Sen University [Guangzhou] (SYSU), Centre Hospitalier National, B.P. 4160, Nouakchott, Mauritania, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), University College of London [London] (UCL), Génétique et Physiologie de l'Audition, Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Collège de France (CdF (institution)), Mouna Hadrami has received a fellowship of 12 months from the SCAC/FRANCE., Mouna Hadrami has received a fellowship of 12 months from the SCAC/FRANCE. We wish to thank Mr. Mohamed Salem BOUH, the director of Blind’s National Association and all the family members for their cooperation and support. - In memory of John A. Trinick., Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)
- Subjects
Male ,MESH: Mutation ,genetic structures ,MESH: Pedigree ,[SDV]Life Sciences [q-bio] ,DNA Mutational Analysis ,MESH: Amino Acid Sequence ,MESH: Base Sequence ,MESH: Child ,Humans ,Family ,Amino Acid Sequence ,Genetic Testing ,MESH: DNA Mutational Analysis ,Child ,MESH: Family ,Genetic Association Studies ,MESH: Genetic Association Studies ,MESH: Humans ,MESH: Mauritius ,MESH: Genetic Testing ,Base Sequence ,MESH: Peptides ,Glaucoma ,MESH: Male ,Pedigree ,Mutation ,Mauritius ,Female ,MESH: Glaucoma ,Peptides ,MESH: Female ,Research Article - Abstract
International audience; Purpose: Intraocular pressure leading to glaucoma is a major cause of childhood blindness in developing countries. In this study, we sought to identify gene variants potentially associated with primary congenital glaucoma (PCG) in the Mauritanian population.Methods: Using next-generation sequencing (NGS), a panel of PCG candidate genes was screened in a search for DNA mutations in four families with multiple occurrences of PCG.Results: Targeted exome sequencing analysis revealed predicted pathogenic mutations in four genes: CYP1B1 (c.217_218delTC, p.Ser73Valfs*150), MYOC (878C>A, p.T293K), NTF4 (c.601T>G, p.Cys201Gly), and WDR36 (c.2078A>G, p.Asn693Ser), each carried by a different family.Conclusions: Genetic variation associated with PCG in this study reflects the ethnic heterogeneity of the Mauritanian population. However, a larger cohort is needed to identify additional families carrying these mutations and confirm their biologic role.
- Published
- 2018
30. Mutations in CDC14A , Encoding a Protein Phosphatase Involved in Hair Cell Ciliogenesis, Cause Autosomal-Recessive Severe to Profound Deafness
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Zied Riahi, Christine Petit, Sébastien Chardenoux, Hala El Hachmi, Crystel Bonnet, Sedigheh Delmaghani, Philippe Herbomel, Isabelle Perfettini, Yosra Bouyacoub, Ahmed Houmeida, Jean-Pierre Hardelin, Asadollah Aghaie, Collège de France - Chaire Génétique et physiologie cellulaire, Collège de France (CdF (institution)), Institut de la Vision, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut Pasteur de Tunis, Réseau International des Instituts Pasteur (RIIP), Laboratoire de Biochimie et Biologie Moléculaire [Nouakchott], Faculté des Sciences et Techniques [Nouakchott, Mauritania], Macrophages et Développement de l’Immunité, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), ED 515 - Complexité du vivant, Université Pierre et Marie Curie - Paris 6 (UPMC), This work was supported by the French state program 'Investissements d’Avenir' (ANR-10-LABX-65), BNP Paribas, and Bucodes SurdiFrance., Chaire Génétique et physiologie cellulaire, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), and HAL-UPMC, Gestionnaire
- Subjects
Adult ,Male ,0301 basic medicine ,Morpholino ,Hearing Loss, Sensorineural ,Nonsense mutation ,Fluorescent Antibody Technique ,[SDV.GEN] Life Sciences [q-bio]/Genetics ,Biology ,Severity of Illness Index ,Mice ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Report ,Ciliogenesis ,Hair Cells, Auditory ,otorhinolaryngologic diseases ,Genetics ,medicine ,Animals ,Humans ,Genetics(clinical) ,Cilia ,Nonsyndromic deafness ,Zebrafish ,Genetics (clinical) ,Aged ,[SDV.GEN]Life Sciences [q-bio]/Genetics ,Cilium ,Middle Aged ,Kinocilium ,medicine.disease ,biology.organism_classification ,Molecular biology ,Phosphoric Monoester Hydrolases ,Pedigree ,030104 developmental biology ,medicine.anatomical_structure ,Larva ,Mutation ,Female ,sense organs ,Hair cell ,Protein Tyrosine Phosphatases ,030217 neurology & neurosurgery - Abstract
International audience; By genetic linkage analysis in a large consanguineous Iranian family with eleven individuals affected by severe to profound congenital deafness, we were able to define a 2.8 Mb critical interval (at chromosome 1p21.2-1p21.1) for an autosomal-recessive nonsyndromic deafness locus (DFNB). Whole-exome sequencing allowed us to identify a CDC14A biallelic nonsense mutation, c.1126C>T (p.Arg376∗), which was present in the eight clinically affected individuals still alive. Subsequent screening of 115 unrelated individuals affected by severe or profound congenital deafness of unknown genetic cause led us to identify another CDC14A biallelic nonsense mutation, c.1015C>T (p.Arg339∗), in an individual originating from Mauritania. CDC14A encodes a protein tyrosine phosphatase. Immunofluorescence analysis of the protein distribution in the mouse inner ear showed a strong labeling of the hair cells’ kinocilia. By using a morpholino strategy to knockdown cdc14a in zebrafish larvae, we found that the length of the kinocilia was reduced in inner-ear hair cells. Therefore, deafness caused by loss-of-function mutations in CDC14A probably arises from a morphogenetic defect of the auditory sensory cells’ hair bundles, whose differentiation critically depends on the proper growth of their kinocilium.
- Published
- 2016
31. A novel missense mutation of
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Mouna, Hadrami, Crystel, Bonnet, Fatimetou, Veten, Christina, Zeitz, Christel, Condroyer, Panfeng, Wang, Mohamed, Biya, Med Ahmed, Sidi Ahmed, Qingjiong, Zhang, Sidi, Cheikh, Isabelle, Audo, Christine, Petit, and Ahmed, Houmeida
- Subjects
Adult ,Genetic Markers ,Male ,Base Sequence ,DNA Mutational Analysis ,Molecular Sequence Data ,Mauritania ,Mutation, Missense ,High-Throughput Nucleotide Sequencing ,Polymerase Chain Reaction ,Cataract ,Connexins ,Pedigree ,Asian People ,Humans ,Female ,Amino Acid Sequence ,Genetic Testing ,Child - Abstract
Inborn lens opacity is the most frequent cause of childhood blindness. In this study, we aimed to define the presumed genetic cause of a congenital cataract present in a Mauritanian family over the last nine generations.A family history of the disease and eye examination were carried out for the family members. Next-generation sequencing using a panel of 116 cataract underlying genes was selectively conducted on the proband's DNA. Nucleotide and amino acid changes and their impact on the phenotype were evaluated using various data analyzing software.Congenital nuclear cataract, with autosomal dominant mode, was observed in the family. All patients had consequences on their vision in the first 2 years of life. Genetic screening revealed a new mutation c.166AC (p.Thr56Pro) inA
- Published
- 2018
32. A novel missense mutation of GJA8 causes congenital cataract in a large Mauritanian family.
- Author
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Hadrami, Mouna, Bonnet, Crystel, Veten, Fatimetou, Zeitz, Christina, Condroyer, Christel, Wang, Panfeng, Biya, Mohamed, Sidi Ahmed, Med Ahmed, Zhang, Qingjiong, Cheikh, Sidi, Audo, Isabelle, Petit, Christine, and Houmeida, Ahmed
- Published
- 2019
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33. A novel missense mutation of GJA8 causes congenital cataract in a large Mauritanian family
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Hadrami, Mouna, primary, Bonnet, Crystel, additional, Veten, Fatimetou, additional, Zeitz, Christina, additional, Condroyer, Christel, additional, Wang, Panfeng, additional, Biya, Mohamed, additional, Sidi Ahmed, Med Ahmed, additional, Zhang, Qingjiong, additional, Cheikh, Sidi, additional, Audo, Isabelle, additional, Petit, Christine, additional, and Houmeida, Ahmed, additional
- Published
- 2018
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34. HLA class I (-A, -B, -C) and class II (-DR, -DQ) polymorphism in the Mauritanian population
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Hamed, Cheikh Tijani, primary, Meiloud, Ghlana, additional, Veten, Fatimetou, additional, Hadrami, Mouna, additional, Ghaber, Sidi M., additional, Boussaty, Ely C., additional, Habti, Norddine, additional, and Houmeida, Ahmed, additional
- Published
- 2018
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35. Frequencies and ethnic distribution of ABO and Rh(D) blood groups in Mauritania: results of first nationwide study
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Sidi M. Ghaber, M A Med Mahmoud, Ahmed Houmeida, B Ba, Cheikh Tijani Hamed, N Habti, Isselmou Abdelhamid, and M A Bollahi
- Subjects
education.field_of_study ,Blood transfusion ,Black african ,medicine.medical_treatment ,Immunology ,Population ,Ethnic group ,General Medicine ,Ethnic origin ,Biology ,ABO blood group system ,Ethnic distribution ,Genetics ,medicine ,education ,Molecular Biology ,Allele frequency ,Genetics (clinical) ,Demography - Abstract
There is no data available on the ABO/Rh(D) frequencies in the Mauritanian population. We retrospectively analysed records of a 5-year database that contained ABO/Rh phenotype and ethnic origin of 10 116 volunteers giving blood at the national blood transfusion centre to derive the frequencies of ABO/Rh(D) groups in the Mauritanian population. The two race categories in the country and their sub-ethnic groups: the Moors (whites and black) and the black Africans (Pulhars, Soninkes and Wolof) were included in this study. Globally, group O had the highest frequency (49.10%) followed by A (28.28%), B (18.56%) and AB (4.05%). This order more common in North African populations was found in four of the five ethnic groups composing our population. Allele frequencies were, respectively, 70.20%, 17.74% and 12.04% giving the same order of O > A > B. We observed no significant variation in these frequencies between the different ethnic groups. Rhesus study showed that with a percentage of 94.23% Rh(D) positive is by far the most prevalent, while Rh(D) negative is present only in 5.77% of the total population. This frequency distribution supports the mixed-race composition of the Mauritanian population.
- Published
- 2011
36. Polymorphism of the Beta Gene in Homozygous Sickle Cell Patients in Senegal and Its Influence on the Main Complications of the Disease
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Sidy Mohamed Seck, Sira Thiam, Marie Pierre Diouf, Fatou Diallo, Blaise Felix Faye, Dominique Doupa, Souleymane Thiam, Saliou Diop, Aminata Lam, Demba Makalou, Abdourahmane Samba, Ousseynou Boye, Ahmed Houmeida, Fatimetou Veten, Pape Matar Kandji, Ibrahima Diagne, Papa Madieye Gueye, Moustapha Djite, and Arame Ndiaye
- Subjects
education.field_of_study ,medicine.medical_specialty ,Population ,Haplotype ,General Medicine ,Biology ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Internal medicine ,Epidemiology ,medicine ,Hemoglobin F ,Hemoglobin ,Restriction fragment length polymorphism ,education ,Prospective cohort study ,Allele frequency ,030215 immunology - Abstract
Sickle cell disease has a great variability of clinical and biological expression that depends on modulatory and environmental genetic factors. This variability in clinical and biological expression encourages us to look for predictors of severity. Hemoglobin F and its genetic determinants are influencing prognostic factors. The objectives of this study were to: determine the prevalence of the Senegal haplotype in homozygous sickle cell patients, study the relationship between this haplotype and the hemoglobin F level and evaluate its influence on the complications of the disease. This is a cross-sectional prospective study that included 100 homozygous sickle cell patients aged over 15 years. A questionnaire was used to collect epidemiological, clinical and biological variables. The hemoglobin F level was measured by capillary method and the analysis of point mutations by restriction fragment length polymorphism (RFLP). These data were collected and analyzed with the software Epi-info 7.2. A value p ≤ 0.05 was considered significant. The Senegal haplotype was found in 90% of patients, of whom 58% were homozygous for this mutation and 32% were heterozygous. The hemoglobin F level averaged 9.5% ± 8.3% and correlated statistically significantly with the allelic frequency. However, only bilary lithiasis correlated with the Senegal haplotype (p
- Published
- 2018
37. Evidence for the Oligomeric State of ‘Elastic’ Titin in Muscle Sarcomeres
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John Trinick, Peter J. Knight, Andy Baron, Walter F. Stafford, Kavitha Thirumurugan, G. Nasir Khan, Larissa Tskhovrebova, Ahmed Houmeida, Jeff N. Keen, and Beatrix Thompson
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Models, Molecular ,Sarcomeres ,animal structures ,Molecular Sequence Data ,Muscle Proteins ,Obscurin ,macromolecular substances ,Sarcomere ,Sequence Analysis, Protein ,Structural Biology ,Myosin ,Animals ,Myocyte ,Myotilin ,Connectin ,Amino Acid Sequence ,Protein Structure, Quaternary ,Molecular Biology ,Actin ,biology ,Chemistry ,musculoskeletal system ,Elasticity ,Peptide Fragments ,Molecular Weight ,Actinin, alpha 2 ,Actin Cytoskeleton ,Microscopy, Electron ,Crystallography ,biology.protein ,Biophysics ,Titin ,Rabbits ,Protein Kinases ,Protein Processing, Post-Translational ,Ultracentrifugation - Abstract
The giant protein titin has important roles in muscle sarcomere integrity, elasticity and contractile activity. The key role in elasticity was highlighted in recent years by single-molecule mechanical studies, which showed a direct relationship between the non-uniform structure of titin and the hierarchical mechanism of its force-extension behavior. Further advances in understanding mechanisms controlling sarcomere structure and elasticity require detailed knowledge of titin arrangement and interactions in situ. Here we present data on the structure and self-interactive properties of an approximately 290 kDa ( approximately 100 nm long) tryptic fragment from the I-band part of titin that is extensible in situ. The fragment includes the conserved 'distal' tandem Ig segment of the molecule and forms side-by-side oligomers with distinctive 4 nm cross-striations. Comparisons between these oligomers and the end filaments seen at the tips of native thick filaments indicate identical structure. This shows that end-filaments are formed by the elastic parts of six titin molecules connecting each end of the thick filament to the Z-line. Self-association of elastic titin into stiff end-filaments adds a further hierarchical level in the mechanism of titin extensibility in muscle cells. Self-association of this part of titin may be required to prevent interference of the individual flexible molecules with myosin cross-bridges interacting with actin.
- Published
- 2008
38. Etiology and associated GJB2 mutations in Mauritanian children with non-syndromic hearing loss
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Christine Bonnet, Ely Cheikh Mohamed Moctar, Hala El Hachmi, Fatimetou Veten, Mohammed Errami, Ahmed Houmeida, Zied Riahi, Sonia Abdelhak, and Ghlana Meiloud
- Subjects
0301 basic medicine ,Adult ,Genetic Markers ,Male ,Pediatrics ,medicine.medical_specialty ,Adolescent ,Hearing loss ,Consanguinity ,Deafness ,Measles ,Connexins ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Gene Frequency ,Risk Factors ,otorhinolaryngologic diseases ,Medicine ,Humans ,Genetic Testing ,Family history ,030223 otorhinolaryngology ,Child ,Allele frequency ,Genetic testing ,medicine.diagnostic_test ,business.industry ,Mauritania ,General Medicine ,medicine.disease ,Connexin 26 ,030104 developmental biology ,Otorhinolaryngology ,Child, Preschool ,Mutation ,Etiology ,Female ,medicine.symptom ,business ,Meningitis - Abstract
Origins of all hearing impairment forms may be divided into genetic mutations and acquired influence. Both carry damage to the inner ear structure resulting in a mild to profound dysfunction of the auditory system. The purpose of this study was to assess the different etiologies of deafness in two reference centers for hearing-impaired children in Nouakchott/Mauritania. Data on gender, age, consanguinity, etiology and family history of deafness were gathered by interviewing the custodians of 139 children with hearing loss. DNA of pupils with hereditary non-syndromic deafness was then screened for GJB2 mutations by sequencing methods. Postnatal hearing loss was found in 36 (25.8 %) out of the 139 children surveyed. The main etiologies of this group were infections caused by meningitis (12.9 %) and measles (2.8 %). Unknown and ototoxic origins accounted for, respectively, 5.7 and 3.5 %. In 103 (74.1 %) children, deafness was identified near after the time of birth and, therefore, presumed as congenital. 56.8 % of deaf children had consanguineous parents. Two GJB2 mutations, c.del35G with an allele frequency of 4.7 % and R32C (3.7 %) were detected. Infections such as meningitis and measles were the most prevalent causes of postnatal deafness. In cases of congenital hearing impairment, two GJB2 allele variants, i.e., del35G and R32C (3.7 %) were detected. Extended genetic testing is recommended for a more comprehensive determination of congenital causes.
- Published
- 2015
39. A novel missense mutation of GJA8causes congenital cataract in a large Mauritanian family
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Hadrami, Mouna, Bonnet, Crystel, Veten, Fatimetou, Zeitz, Christina, Condroyer, Christel, Wang, Panfeng, Biya, Mohamed, Sidi Ahmed, Med Ahmed, Zhang, Qingjiong, Cheikh, Sidi, Audo, Isabelle, Petit, Christine, and Houmeida, Ahmed
- Abstract
Objective of the study: Inborn lens opacity is the most frequent cause of childhood blindness. In this study, we aimed to define the presumed genetic cause of a congenital cataract present in a Mauritanian family over the last nine generations.Methods: A family history of the disease and eye examination were carried out for the family members. Next-generation sequencing using a panel of 116 cataract underlying genes was selectively conducted on the proband’s DNA. Nucleotide and amino acid changes and their impact on the phenotype were evaluated using various data analyzing software.Results: Congenital nuclear cataract, with autosomal dominant mode, was observed in the family. All patients had consequences on their vision in the first 2 years of life. Genetic screening revealed a new mutation c.166A>C (p.Thr56Pro) in GJA8, encoding the Cx50 α-connexin protein. This mutation co-segregated in all patients and was not observed in the unaffected family members and controls. The predicted secondary structure impacted by p.Thr56Pro revealed a localized disruption, in the first extra membrane loop of the wild-type sheet, which is replaced in the mutant protein by a turn then a coil. This conformational change was functionally predicted as probably damaging.Conclusion: A new mutation(c.166A>C) in GJA8 underlying a nuclear congenital cataract was identified in this study.Its segregation with the phenotype might be useful as a predicting marker of the disease.
- Published
- 2019
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40. Mutation profile of glaucoma candidate genes in Mauritanian families with primary congenital glaucoma.
- Author
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Hadrami, Mouna, Bonnet, Crystel, Zeitz, Christina, Veten, Fatimetou, Biya, Med, Hamed, Cheikh T., Condroyer, Christel, Panfeng Wang, Sidi, Med Mahmoud, Cheikh, Sidi, Qingjiong Zhang, Audo, Isabelle, Petit, Christine, and Houmeida, Ahmed
- Published
- 2019
41. mtDNA 16184–16193 poly-C tract does not predispose to type 2 diabetes in the Mauritanian population
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Khaled Lasram, Abdoulaye Samb, Sonia Abdelhak, Rym Kefi, Ghlana Meiloud, Ahmed Houmeida, and Isselmou Abdelhamid
- Subjects
education.field_of_study ,Mitochondrial DNA ,medicine.medical_specialty ,business.industry ,Endocrinology, Diabetes and Metabolism ,Population ,Type 2 diabetes ,medicine.disease ,Endocrinology ,Diabetes mellitus ,Internal medicine ,Internal Medicine ,medicine ,education ,business - Published
- 2013
42. Study of the T16189C variant and mitochondrial lineages in Tunisian and overall Mediterranean region
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Imen Arfa, Rym Kefi, Slim Ben Ammar, Emna Kerkeni, Abdelhamid Barakat, Henda Jamoussi, Ahmed Houmeida, Ghlana Meiloud, Sonia Abdelhak, Lilia Romdhane, Sonia Bahri, Nizar Ben Halim, Khaled Lasram, Abdelmajid Abid, Sana Hsouna, Child Neurological Diseases Unit, Faculté de Médecine de Tunis, Université de Tunis El Manar (UTM)-Université de Tunis El Manar (UTM), Laboratoire de Génomique Biomédicale et Oncogénétique - Biomedical Genomics and Oncogenetics Laboratory (LR11IPT05), Université de Tunis El Manar (UTM)-Institut Pasteur de Tunis, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Laboratoire de Biochimie et Biologie Moléculaire, Faculté des Sciences et Techniques, Université de Tunis El Manar (UTM), National Institute of Nutrition and Food Technology, Department of External Consultation, 11 rue Jebel Lakhdar, Bab Saadoun, 1007 Tunis, Tunisia., Laboratoire central de biologie médicale, Institut Pasteur de Tunis, Institut Pasteur de Tunis, Département de la Recherche Scientifique, Laboratoire de Génétique Moléculaire Humaine, Institut Pasteur du Maroc, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut Pasteur du Maroc, Laboratoire de Biochimie et Biologie Moléculaire [Nouakchott], and Faculté des Sciences et Techniques [Nouakchott, Mauritania]
- Subjects
0301 basic medicine ,Mediterranean climate ,Mitochondrial DNA ,Principal Component Analysis ,Tunisia ,Mediterranean Region ,Genetic Variation ,Sequence Analysis, DNA ,Biology ,Positive correlation ,DNA, Mitochondrial ,Haplogroup ,Hypervariable region ,03 medical and health sciences ,030104 developmental biology ,Haplotypes ,Evolutionary biology ,Phylogenetics ,Genetics ,Humans ,North african ,Negative correlation ,Molecular Biology ,ComputingMilieux_MISCELLANEOUS ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology - Abstract
The mitochondrial DNA (mtDNA) variant T16189C has been investigated in several metabolic diseases. In this study, we aimed to estimate the frequency of the T16189C variant in Tunisian and other Mediterranean populations and to evaluate the impact of this variant on the phylogeny of Mediterranean populations. Blood sample of 240 unrelated Tunisian subjects were recruited from several Tunisian localities. The hypervariable region 1 of the mtDNA were amplified and sequenced. Additional sequences (N = 4921) from Mediterranean populations were compiled from previous studies. The average frequency of T16189C variant in Tunisia (29%) is similar to that observed in North African and Near Eastern populations. Our findings showed positive correlation of the T16189C variant with Sub-Saharan and North African lineages, while a negative correlation was found with the Eurasian haplogroups, reaching its maximum with the Eurasian haplogroup H. The principal component analyses showed a high internal heterogeneity between Tunisian localities. At the Mediterranean scale, Tunisians are closer to North African (Algerian and Moroccan) and Near Eastern populations (Syrians and Palestinians) than to Europeans.
- Published
- 2014
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43. Mutations in CDC14A , Encoding a Protein Phosphatase Involved in Hair Cell Ciliogenesis, Cause Autosomal-Recessive Severe to Profound Deafness
- Author
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Delmaghani, Sedigheh, primary, Aghaie, Asadollah, additional, Bouyacoub, Yosra, additional, El Hachmi, Hala, additional, Bonnet, Crystel, additional, Riahi, Zied, additional, Chardenoux, Sebastien, additional, Perfettini, Isabelle, additional, Hardelin, Jean-Pierre, additional, Houmeida, Ahmed, additional, Herbomel, Philippe, additional, and Petit, Christine, additional
- Published
- 2016
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44. Study of the T16189C variant and mitochondrial lineages in Tunisian and overall Mediterranean region
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Abdelhamid Barakat, Sonia Abdelhak, Rym Kefi, Sana Hsouna, Nizar Ben Halim, Khaled Lasram, Ghlana Meiloud, Imen Arfa, Emna Kerkeni, Lilia Romdhane, Henda Jamoussi, Sonia Bahri, Slim Ben Ammar, Abdelmajid Abid, Ahmed Houmeida, Abdelhamid Barakat, Sonia Abdelhak, Rym Kefi, Sana Hsouna, Nizar Ben Halim, Khaled Lasram, Ghlana Meiloud, Imen Arfa, Emna Kerkeni, Lilia Romdhane, Henda Jamoussi, Sonia Bahri, Slim Ben Ammar, Abdelmajid Abid, and Ahmed Houmeida
- Published
- 2015
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45. Occurrence of the Codon 24 (A > T) Mutation in the Mauritanian Population
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Ahmed Houmeida, Sidi M. Ghaber, Fatimetou Veten, and Nordine Habti
- Subjects
Adult ,Erythrocyte Indices ,Male ,Genetics ,education.field_of_study ,Adolescent ,Thalassemia ,beta-Thalassemia ,Biochemistry (medical) ,Clinical Biochemistry ,Population ,Mauritania ,beta-Globins ,Hematology ,Biology ,medicine.disease ,DNA sequencing ,Mutation ,Mutation (genetic algorithm) ,medicine ,Humans ,Female ,Codon ,education ,Genetics (clinical) - Abstract
Using direct DNA sequencing, we identified the codon 24 (A > T) (HBB: c.72T > A, p.Gly24Gly), mutation in two out of 15 Mauritanian β-thalassemia (β-thal) carriers. Both were of Black origin and had hematological indices compatible with mild β-thal minor. Could this variant be more common than expected in the Black Mauritanian population?
- Published
- 2015
46. E23K variant in KCNJ11 gene is associated with susceptibility to type 2 diabetes in the Mauritanian population
- Author
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Ahmed Houmeida, Sonia Abdelhak, Khaled Lasram, Abdoulaye Samb, Rym Kefi, Nizar Ben Halim, Isselmou Abdelhamid, Ghlana Meiloud, Centre Hospitalier National, B.P. 4160, Nouakchott, Mauritania, Laboratoire de Génomique Biomédicale et Oncogénétique - Biomedical Genomics and Oncogenetics Laboratory (LR11IPT05), Université de Tunis El Manar (UTM)-Institut Pasteur de Tunis, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Laboratoire de Biochimie et Biologie Moléculaire, Faculté des Sciences et Techniques, Département de Chimie Biologique, UCAD, Dakar, Senegal., Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), and This work was supported by NEPAD/NABNet TYPE 2 DIABETES-NA (New Partnership for Africa’s Development, North Africa Biosciences Network), joint WHO/EMRO-COMSTECH RAB&GH grants
- Subjects
Oncology ,Male ,Endocrinology, Diabetes and Metabolism ,[SDV]Life Sciences [q-bio] ,Type 2 diabetes ,0302 clinical medicine ,Gene Frequency ,Risk Factors ,Genotype ,Odds Ratio ,2. Zero hunger ,0303 health sciences ,education.field_of_study ,Nutrition and Dietetics ,Diabetes ,Mauritania ,Middle Aged ,3. Good health ,Phenotype ,Female ,Family Practice ,E23K ,Adult ,medicine.medical_specialty ,Population ,030209 endocrinology & metabolism ,Single-nucleotide polymorphism ,Polymorphism, Single Nucleotide ,03 medical and health sciences ,Internal medicine ,Diabetes mellitus ,Internal Medicine ,medicine ,SNP ,Humans ,Genetic Predisposition to Disease ,Genetic Testing ,Potassium Channels, Inwardly Rectifying ,education ,Genotyping ,Genetic Association Studies ,030304 developmental biology ,Genetic association ,[SDV.GEN.GPO]Life Sciences [q-bio]/Genetics/Populations and Evolution [q-bio.PE] ,business.industry ,medicine.disease ,Logistic Models ,Diabetes Mellitus, Type 2 ,Case-Control Studies ,Multivariate Analysis ,business - Abstract
Aims Many genetic association studies reported the contribution of KCNJ11 gene to type 2 diabetes susceptibility in different populations. We aimed to evaluate the association between E23K variant of KCNJ11 and type 2 diabetes in the Mauritanian population. Materials and methods We performed a case-control association study including 135 type 2 diabetes Mauritanian patients and 135 controls. Genotyping for the E23K variant was performed using a TaqMan allelic discrimination assay. Results We found significant association between KCNJ11 E23K variant and type 2 diabetes (Global model, OR=2.08, 95% CI=1.09–3.97, p =0.026). In the Moor ethnic group, E23K was also associated with type 2 diabetes in the general model (OR=2.08, 95% CI=1.09–3.97, p =0.026) and under the dominant model (OR=2.49, 95% CI=1.12–5.55, p =0.026). In the Mauritanians of African descent, KK genotype was not found. Besides, E23K variant was not associated with type 2 diabetes (OR=0.69, 95% CI=0.04–11.32, p =0.793). Conclusions Our results revealed the risk of type 2 diabetes conferred by KCNJ11 E23K gene variant in the Mauritanian population.
- Published
- 2013
47. Type 2 diabetes in Mauritania: Prevalence of the undiagnosed diabetes, influence of family history and maternal effect
- Author
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Khaled Lasram, Ahmed Houmeida, Sonia Abdelhak, Rym Kefi, Imen Arfa, Isselmou Abdelhamid, Abdallahi Sidi Mhamed, Nizar Ben Halim, Ghlana Meiloud, Abdoulaye Samb, Fatimetou Veten, Laboratoire de Biochimie et Biologie Moléculaire [Nouakchott], Faculté des Sciences et Techniques [Nouakchott, Mauritania], Laboratoire de Génomique Biomédicale et Oncogénétique - Biomedical Genomics and Oncogenetics Laboratory (LR11IPT05), Université de Tunis El Manar (UTM)-Institut Pasteur de Tunis, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Department of Internal Medicine, Centre Hospitalier National, Laboratory of Chemistry, and Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)
- Subjects
Blood Glucose ,Male ,Proband ,Heredity ,Endocrinology, Diabetes and Metabolism ,[SDV]Life Sciences [q-bio] ,Type 2 diabetes ,0302 clinical medicine ,Risk Factors ,Surveys and Questionnaires ,Prevalence ,Medicine ,030212 general & internal medicine ,Young adult ,Family history ,2. Zero hunger ,education.field_of_study ,Nutrition and Dietetics ,Diabetes ,Maternal effect ,Mauritania ,Fasting ,Middle Aged ,Pedigree ,3. Good health ,Phenotype ,Female ,Family Practice ,Adult ,Population ,Mothers ,030209 endocrinology & metabolism ,Young Adult ,03 medical and health sciences ,Diabetes mellitus ,Internal Medicine ,Humans ,Effect ,Genetic Predisposition to Disease ,education ,Chi-Square Distribution ,business.industry ,medicine.disease ,Health Surveys ,Diabetes Mellitus, Type 2 ,business ,Chi-squared distribution ,Biomarkers ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology ,Demography - Abstract
International audience; Aim: We estimated the prevalence of undiagnosed diabetes, analyzed the influence of family history on the occurrence of T2D and evaluated its aggregation pattern in the Mauritanian population. Methods: The prevalence of unknown diabetes was obtained using data compiled from 1278 Mauritanian adults applying a questionnaire and fasting serum glucose tests. Detailed family history of diabetes and clinical characteristics were gathered from 421 T2D patients. Results: The prevalence of undiagnosed diabetes was 4.7 +/- 1.2% in the studied population (3.1% in men and 6.4% in women). 27% of T2D patients reported at least one relative with diabetes. Association between family history and diabetes was higher among first degree compared to second degree relatives (p = 0.003). We observed more probands with an affected mother than those who have a father with diabetes (p = 0.002), suggesting a preferential maternal effect which did not extend to second degree relatives. Conclusions: These results show that the prevalence of diabetes in the Mauritanian population could be higher than currently thought. Family history screening may be used in the management of this condition in Mauritania. (C) 2012 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.
- Published
- 2013
48. Distribution of Rhesus and Kell blood group frequencies in the Mauritanian population
- Author
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Hamed, Cheikh Tijani, Bollahi, Mohamed Abdalalh, Abdelhamid, Isselmou, Sow, Amadou, Sidi, Abdallah Mhamed, Habti, Nouredine, and Houmeida, Ahmed
- Subjects
Male ,Rh-Hr Blood-Group System ,Gene Frequency ,Kell Blood-Group System ,Mauritania ,Prevalence ,Humans ,Blood Donors ,Female ,Letter to the Editor ,Alleles - Published
- 2013
49. Studies of the interaction between titin and myosin
- Author
-
J Holt, L Tskhovrebova, John Trinick, and A Houmeida
- Subjects
Myosin light-chain kinase ,animal structures ,Molecular Sequence Data ,Muscle Proteins ,macromolecular substances ,Myosins ,Myosin head ,chemistry.chemical_compound ,Myosin ,Animals ,Connectin ,Drug Interactions ,Amino Acid Sequence ,Cyanogen Bromide ,Binding site ,Peptide sequence ,Chromatography, High Pressure Liquid ,Meromyosin ,biology ,Myosin Subfragments ,Membrane Proteins ,Cell Biology ,Articles ,musculoskeletal system ,Microscopy, Electron ,chemistry ,Biochemistry ,Immunoglobulin J-Chains ,biology.protein ,Biophysics ,Titin ,Cyanogen bromide ,Rabbits ,Protein Kinases ,Protein Binding - Abstract
The interaction of titin with myosin has been studied by binding assays and electron microscopy. Electron micrographs of the titin-myosin complex suggest a binding site near the tip of the tail of the myosin molecule. The distance from the myosin head-tail junction to titin indicates binding 20-30 nm from the myosin COOH terminus. Consistent with this, micrographs of titin-light meromyosin (LMM) show binding near the end of the LMM molecule. Plots of myosin- and LMM-attachment positions along the titin molecule show binding predominantly in the region located in the A band in situ, which is consistent with the proposal that titin regulates thick filament assembly. Estimates of the apparent dissociation constant of the titin-LMM complex were approximately 20 nM. Assays of LMM cyanogen bromide fragments also suggested a strong binding site near the COOH terminus. Proteolysis of a COOH-terminal 17.6-kD CNBr fragment isolated from whole myosin resulted in eight peptides of which only one, comprising 17 residues, bound strongly to titin. Two isoforms of this peptide were detected by protein sequencing. Similar binding data were obtained using synthetic versions of both isoforms. The peptide is located immediately COOH-terminal of the fourth "skip" residue in the myosin tail, which is consistent with the electron microscopy. Skip-4 may have a role in determining thick filament structure, by allowing abrupt bending of the myosin tail close to the titin-binding site.
- Published
- 1995
50. Hb S [β6(A3)Glu→Val, GAGGTG] and β-globin gene cluster haplotype distribution in Mauritania
- Author
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Salem Abbes, Ahmed Houmeida, Mohamed Lemine Ould Salem, Isselmou Abdelhamid, Ghlana Meiloud, Sidi M. Ghaber, and Fatimetou Veten
- Subjects
Genetics ,Male ,education.field_of_study ,Black african ,Genotype ,Biochemistry (medical) ,Clinical Biochemistry ,Haplotype ,Population ,Hemoglobin, Sickle ,β globin gene ,Mauritania ,Racial group ,Hematology ,beta-Globins ,Biology ,Disease cluster ,Gene Frequency ,Haplotypes ,Multigene Family ,Humans ,Female ,Hemoglobin hb ,education ,Genetics (clinical) - Abstract
Of 1050 Mauritanian blood donors screened from the two main racial groups, i.e., the Moors and Black Africans, 60 were found to carry Hb S [β6(A3)Glu→Val, GAG >GTG], giving a global frequency of 5.71%. The prevalence observed in the Black African Mauritanians (10.69%) is almost five times that found in the Moor group (2.25%). Four of the five main βS haplotypes were detected in this study: Senegal (77.8%), Benin (8.8%), Arab-Indian (5.5%) and Bantu (4.4%). These data showed that Hb S is a serious public health problem in Mauritania. They also confirm the ethnic heterogeneity of the Mauritanian population.
- Published
- 2012
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