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Elmaihub ES, Alhudiri I, Ramadan AM, Eljilani M, Elzagheid A, Elfagi F, Hassen E. Analysis of BRCA1 germline variants (exons 5, 11 and 20) in breast cancer families from Libya. Libyan J Med 2024; 19:2356906. [PMID: 38785139 DOI: 10.1080/19932820.2024.2356906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
Breast cancer (BC) is a leading cause of cancer deaths in Libyan women. BRCA1 variants differ globally due to the diversity of genetic makeup and populations history. Their distribution, prevalence, and significance in Libyans remain largely unexplored. This study investigated the characteristics and distribution of BRCA1 variants in exons 5, 11, and 20 in Libyan families with BC. Thirty-six BC patients at ≤ 45 years, between 46-50 years and with a family history of breast, ovarian, pancreatic or prostate cancer in close relatives, or with triple-negative BC, were selected from 33 unrelated families during 2018-2020 at the National Cancer Institute, Sabratha, Libya. From these 33 families, 20 women (18 BC patients and two unaffected) were screened for BRCA1 exons 5, 11 and 20 using Sanger sequencing. All families completed an epidemiology and family history questionnaire. Twenty-seven variants (26 in exon 11 and 1 in exon 20, minor allele frequency of < 0.01) were detected in 10 of 18 unrelated families (55.6%.) Among the 27 variants, 26 (96%) were heterozygous. A frameshift pathogenic variant, c.2643del, and one novel variant c.1366A>G were identified. Furthermore, seven variants with unknown clinical significance were detected: c.1158T>A, c.1346C>G, c.1174C>G, c.3630 G>T, c.3599A>T, and c.3400 G>C in exon 11, and c.5244T>A in exon 20. Six variants with conflicting pathogenicity interpretations, c. 3460T>A, c. 3572 G>A, c. 3700 G>C, c. 1246C>G, c. 1344C>G, and c. 1054 G>A, were also identified. Twelve benign/likely benign variants were identified. Rare BRCA1 variants that have not been reported in North Africa were found in Libyan patients. These findings provide preliminary insights into the BRCA1 variants that could contribute to hereditary BC risk in Libyans. Further functional, computational, and population analyses are essential to determine their significance and potential impact on BC risk, which could ultimately lead to more personalized management strategies.
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Affiliation(s)
- Eanas Saleh Elmaihub
- Department of Molecular Biology, Higher Institute of Biotechnology of Monastir, Monastir University, Monastir, Tunisia
- Department of Molecular Biology and Biochemistry, Faculty of Sciences, Sabratha University, Sabratha, Libya
| | - Inas Alhudiri
- Department of Genetic Engineering, Libyan Biotechnology Research Centre, Tripoli, Libya
| | - Ahmad M Ramadan
- Department of Genetic Engineering, Libyan Biotechnology Research Centre, Tripoli, Libya
| | - Mouna Eljilani
- Department of Genetic Engineering, Libyan Biotechnology Research Centre, Tripoli, Libya
| | - Adam Elzagheid
- Department of Genetic Engineering, Libyan Biotechnology Research Centre, Tripoli, Libya
| | - Fakria Elfagi
- Department of Oncology, National Cancer Institute, Sabratha, Libya
| | - Elham Hassen
- Department of Molecular Biology, Higher Institute of Biotechnology of Monastir, Monastir University, Monastir, Tunisia
- Laboratory of Molecular Immuno-Oncology, Faculty of Medicine, Monastir University, Monastir, Tunisia
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Kabbage M, Ben Aissa-Haj J, Othman H, Jaballah-Gabteni A, Laarayedh S, Elouej S, Medhioub M, Kettiti HT, Khsiba A, Mahmoudi M, BelFekih H, Maaloul A, Touinsi H, Hamzaoui L, Chelbi E, Abdelhak S, Boubaker MS, Azzouz MM. A Rare MSH2 Variant as a Candidate Marker for Lynch Syndrome II Screening in Tunisia: A Case of Diffuse Gastric Carcinoma. Genes (Basel) 2022; 13:genes13081355. [PMID: 36011265 PMCID: PMC9407052 DOI: 10.3390/genes13081355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/17/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022] Open
Abstract
Several syndromic forms of digestive cancers are known to predispose to early-onset gastric tumors such as Hereditary Diffuse Gastric Cancer (HDGC) and Lynch Syndrome (LS). LSII is an extracolonic cancer syndrome characterized by a tumor spectrum including gastric cancer (GC). In the current work, our main aim was to identify the mutational spectrum underlying the genetic predisposition to diffuse gastric tumors occurring in a Tunisian family suspected of both HDGC and LS II syndromes. We selected the index case “JI-021”, which was a woman diagnosed with a Diffuse Gastric Carcinoma and fulfilling the international guidelines for both HDGC and LSII syndromes. For DNA repair, a custom panel targeting 87 candidate genes recovering the four DNA repair pathways was used. Structural bioinformatics analysis was conducted to predict the effect of the revealed variants on the functional properties of the proteins. DNA repair genes panel screening identified two variants: a rare MSH2 c.728G>A classified as a variant with uncertain significance (VUS) and a novel FANCD2 variant c.1879G>T. The structural prediction model of the MSH2 variant and electrostatic potential calculation showed for the first time that MSH2 c.728G>A is likely pathogenic and is involved in the MSH2-MLH1 complex stability. It appears to affect the MSH2-MLH1 complex as well as DNA-complex stability. The c.1879G>T FANCD2 variant was predicted to destabilize the protein structure. Our results showed that the MSH2 p.R243Q variant is likely pathogenic and is involved in the MSH2-MLH1 complex stability, and molecular modeling analysis highlights a putative impact on the binding with MLH1 by disrupting the electrostatic potential, suggesting the revision of its status from VUS to likely pathogenic. This variant seems to be a shared variant in the Mediterranean region. These findings emphasize the importance of testing DNA repair genes for patients diagnosed with diffuse GC with suspicion of LSII and colorectal cancer allowing better clinical surveillance for more personalized medicine.
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Affiliation(s)
- Maria Kabbage
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Correspondence:
| | - Jihenne Ben Aissa-Haj
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
| | - Houcemeddine Othman
- Sydney Brenner Institute for Molecular Bioscience, University of the Witwatersrand, Johannesburg 2000, South Africa;
| | - Amira Jaballah-Gabteni
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
| | - Sarra Laarayedh
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
| | - Sahar Elouej
- Marseille Medical Genetics, Aix Marseille University, INSERM, 13007 Marseille, France;
| | - Mouna Medhioub
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Gastroenterology Department, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
| | - Haifa Tounsi Kettiti
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
| | - Amal Khsiba
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Gastroenterology Department, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
| | - Moufida Mahmoudi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Gastroenterology Department, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
| | - Houda BelFekih
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Department of Oncology, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
| | - Afifa Maaloul
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
| | - Hassen Touinsi
- Department of Surgery, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia;
| | - Lamine Hamzaoui
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Gastroenterology Department, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
| | - Emna Chelbi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Department of Pathology, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
| | - Mohamed Samir Boubaker
- Department of Human and Experimental Pathology, Institut Pasteur de Tunis, Tunis 1002, Tunisia; (J.B.A.-H.); (A.J.-G.); (S.L.); (H.T.K.); (A.M.); (M.S.B.)
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
| | - Mohamed Mousaddak Azzouz
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, Tunis EL Manar University, Tunis 1002, Tunisia; (M.M.); (A.K.); (M.M.); (H.B.); (L.H.); (E.C.); (S.A.); (M.M.A.)
- Gastroenterology Department, Mohamed Tahar Maamouri Hospital, Nabeul 8000, Tunisia
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ElBiad O, Laraqui A, El Boukhrissi F, Mounjid C, Lamsisi M, Bajjou T, Elannaz H, Lahlou AI, Kouach J, Benchekroune K, Oukabli M, Chahdi H, Ennaji MM, Tanz R, Sbitti Y, Ichou M, Ennibi K, Badaoui B, Sekhsokh Y. Prevalence of specific and recurrent/founder pathogenic variants in BRCA genes in breast and ovarian cancer in North Africa. BMC Cancer 2022; 22:208. [PMID: 35216584 PMCID: PMC8876448 DOI: 10.1186/s12885-022-09181-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/24/2021] [Indexed: 12/11/2022] Open
Abstract
Background Elucidation of specific and recurrent/founder pathogenic variants (PVs) in BRCA (BRCA1 and BRCA2) genes can make the genetic testing, for breast cancer (BC) and/or ovarian cancer (OC), affordable for developing nations. Methods To establish the knowledge about BRCA PVs and to determine the prevalence of the specific and recurrent/founder variants in BRCA genes in BC and/or OC women in North Africa, a systematic review was conducted in Morocco, Algeria, and Tunisia. Results Search of the databases yielded 25 relevant references, including eleven studies in Morocco, five in Algeria, and nine in Tunisia. Overall, 15 studies investigated both BRCA1 and BRCA2 genes, four studies examined the entire coding region of the BRCA1 gene, and six studies in which the analysis was limited to a few BRCA1 and/or BRCA2 exons. Overall, 76 PVs (44 in BRCA1 and32 in BRCA2) were identified in 196 BC and/or OC patients (129 BRCA1 and 67 BRCA2 carriers). Eighteen of the 76 (23.7%) PVs [10/44 (22.7%) in BRCA1 and 8/32 (25%) in BRCA2] were reported for the first time and considered to be novel PVs. Among those identified as unlikely to be of North African origin, the BRCA1 c.68_69del and BRCA1 c.5266dupC Jewish founder alleles and PVs that have been reported as recurrent/founder variants in European populations (ex: BRCA1 c.181T>G, BRCA1 c1016dupA). The most well characterized PVs are four in BRCA1 gene [c.211dupA (14.7%), c.798_799detTT (14%), c.5266dup (8.5%), c.5309G>T (7.8%), c.3279delC (4.7%)] and one in BRCA2 [c.1310_1313detAAGA (38.9%)]. The c.211dupA and c.5309G>T PVs were identified as specific founder variants in Tunisia and Morocco, accounting for 35.2% (19/54) and 20.4% (10/49) of total established BRCA1 PVs, respectively. c.798_799delTT variant was identified in 14% (18/129) of all BRCA1 North African carriers, suggesting a founder allele. A broad spectrum of recurrent variants including BRCA1 3279delC, BRCA1 c.5266dup and BRCA2 c.1310_1313detAAGA was detected in 42 patients. BRCA1 founder variants explain around 36.4% (47/129) of BC and outnumber BRCA2 founder variants by a ratio of ≈3:1. Conclusions Testing BC and/or OC patients for the panel of specific and recurrent/founder PVs might be the most cost-effective molecular diagnosis strategy.
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Affiliation(s)
- Oubaida ElBiad
- Laboratoire de Recherche et de Biosécurité P3, Hôpital Militaire d'Instruction Mohammed V, Rabat, Maroc. .,Unité de séquençage, Laboratoire de Virologie, Centre de Virologie, des Maladies Infectieuses et Tropicales, Hôpital Militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc. .,Laboratoire de Biodiversité, Ecologie et Génome, Faculté des Sciences, Université Mohammed V, Rabat, Maroc.
| | - Abdelilah Laraqui
- Laboratoire de Recherche et de Biosécurité P3, Hôpital Militaire d'Instruction Mohammed V, Rabat, Maroc.,Unité de séquençage, Laboratoire de Virologie, Centre de Virologie, des Maladies Infectieuses et Tropicales, Hôpital Militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc.,Centre de virologie, des maladies infectieuses et tropicales, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Fatima El Boukhrissi
- Laboratoire de Biochimie-Toxicologie, Hôpital Militaire Moulay Ismail Meknès, Faculté de Médecine et de Pharmacie, Université Sidi Mohamed Ben Abdellah, Fès, Maroc
| | - Chaimaa Mounjid
- Laboratoire de Recherche et de Biosécurité P3, Hôpital Militaire d'Instruction Mohammed V, Rabat, Maroc
| | - Maryame Lamsisi
- Laboratoire de Virologie, Microbiologie, Qualité, Biotechnologies/Ecotoxicologie et Biodiversité, Faculté des sciences et techniques, Mohammadia, Université Hassan II, Casa, Maroc
| | - Tahar Bajjou
- Laboratoire de Recherche et de Biosécurité P3, Hôpital Militaire d'Instruction Mohammed V, Rabat, Maroc
| | - Hicham Elannaz
- Unité de séquençage, Laboratoire de Virologie, Centre de Virologie, des Maladies Infectieuses et Tropicales, Hôpital Militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc.,Centre de virologie, des maladies infectieuses et tropicales, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Amine Idriss Lahlou
- Unité de séquençage, Laboratoire de Virologie, Centre de Virologie, des Maladies Infectieuses et Tropicales, Hôpital Militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc.,Centre de virologie, des maladies infectieuses et tropicales, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Jaouad Kouach
- Service de Gynécologie Obstétrique, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Khadija Benchekroune
- Service de Gynécologie Obstétrique, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Mohammed Oukabli
- Laboratoire d'Anatomopathologie, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Hafsa Chahdi
- Laboratoire d'Anatomopathologie, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Moulay Mustapha Ennaji
- Laboratoire de Virologie, Microbiologie, Qualité, Biotechnologies/Ecotoxicologie et Biodiversité, Faculté des sciences et techniques, Mohammadia, Université Hassan II, Casa, Maroc
| | - Rachid Tanz
- Service d'Oncologie Médicale, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Yassir Sbitti
- Service d'Oncologie Médicale, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Mohammed Ichou
- Service d'Oncologie Médicale, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Khalid Ennibi
- Unité de séquençage, Laboratoire de Virologie, Centre de Virologie, des Maladies Infectieuses et Tropicales, Hôpital Militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc.,Centre de virologie, des maladies infectieuses et tropicales, Hôpital militaire d'Instruction Mohammed V, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Bouabid Badaoui
- Laboratoire de Biodiversité, Ecologie et Génome, Faculté des Sciences, Université Mohammed V, Rabat, Maroc
| | - Yassine Sekhsokh
- Laboratoire de Recherche et de Biosécurité P3, Hôpital Militaire d'Instruction Mohammed V, Rabat, Maroc
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Abdel-Razeq H, Abujamous L, Abunasser M, Edaily S, Bater R. Prevalence and predictors of germline BRCA1 and BRCA2 mutations among young patients with breast cancer in Jordan. Sci Rep 2021; 11:14906. [PMID: 34290354 PMCID: PMC8295261 DOI: 10.1038/s41598-021-94403-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 06/24/2021] [Indexed: 11/09/2022] Open
Abstract
BRCA1 and BRCA2 mutations are not uncommon in breast cancer patients. Western studies show that such mutations are more prevalent among younger patients. This study evaluates the prevalence of germline mutations in BRCA1 and BRCA2 among breast cancer patients diagnosed at age 40 or younger in Jordan. Blood samples of patients with breast cancer diagnosed at age 40 years or younger were obtained for DNA extraction and BRCA sequencing. Mutations were classified as benign/likely benign (non-carrier), pathogenic/likely pathogenic variant (carrier) and variant of uncertain significance (VUS). Genetic testing and counseling were completed on 616 eligible patients. Among the whole group, 75 (12.2%) had pathogenic or likely pathogenic variants; two of the BRCA2 mutations were novel. In multivariate analysis, triple-negative disease (Odd Ratio [OR]: 5.37; 95% CI 2.88-10.02, P < 0.0001), breast cancer in ≥ 2 family members (OR: 4.44; 95% CI 2.52-7.84, P < 0.0001), and a personal history ≥ 2 primary breast cancers (OR: 3.43; 95% CI 1.62-7.24, P = 0.001) were associated with higher mutation rates. In conclusion, among young Jordanian patients with breast cancer, mutation rates are significantly higher in patients with triple-negative disease, personal history of breast cancer and those with two or more close relatives with breast cancer.
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Affiliation(s)
- Hikmat Abdel-Razeq
- Department of Internal Medicine, King Hussein Cancer Center, Queen Rania Al Abdullah Street, P.O. Box: 1269, Amman, 11941, Jordan.
- School of Medicine, University of Jordan, Amman, Jordan.
| | - Lama Abujamous
- Department of Cell Therapy & Applied Genomic, King Hussein Cancer Center, Amman, Jordan
| | - Mahmoud Abunasser
- Department of Internal Medicine, King Hussein Cancer Center, Queen Rania Al Abdullah Street, P.O. Box: 1269, Amman, 11941, Jordan
| | - Sara Edaily
- Department of Internal Medicine, King Hussein Cancer Center, Queen Rania Al Abdullah Street, P.O. Box: 1269, Amman, 11941, Jordan
| | - Rayan Bater
- Department of Internal Medicine, King Hussein Cancer Center, Queen Rania Al Abdullah Street, P.O. Box: 1269, Amman, 11941, Jordan
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5
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Rotimi SO, Rotimi OA, Salhia B. A Review of Cancer Genetics and Genomics Studies in Africa. Front Oncol 2021; 10:606400. [PMID: 33659210 PMCID: PMC7917259 DOI: 10.3389/fonc.2020.606400] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/14/2020] [Indexed: 12/24/2022] Open
Abstract
Cancer is the second leading cause of death globally and is projected to overtake infectious disease as the leading cause of mortality in Africa within the next two decades. Cancer is a group of genomic diseases that presents with intra- and inter-population unique phenotypes, with Black populations having the burden of morbidity and mortality for most types. At large, the prevention and treatment of cancers have been propelled by the understanding of the genetic make-up of the disease of mostly non-African populations. By the same token, there is a wide knowledge gap in understanding the underlying genetic causes of, and genomic alterations associated with, cancer among black Africans. Accordingly, we performed a review of the literature to survey existing studies on cancer genetics/genomics and curated findings pertaining to publications across multiple cancer types conducted on African populations. We used PubMed MeSH terms to retrieve the relevant publications from 1990 to December 2019. The metadata of these publications were extracted using R text mining packages: RISmed and Pubmed.mineR. The data showed that only 0.329% of cancer publications globally were on Africa, and only 0.016% were on cancer genetics/genomics from Africa. Although the most prevalent cancers in Africa are cancers of the breast, cervix, uterus, and prostate, publications representing breast, colorectal, liver, and blood cancers were the most frequent in our review. The most frequently reported cancer genes were BRCA1, BRCA2, and TP53. Next, the genes reported in the reviewed publications’ abstracts were extracted and annotated into three gene ontology classes. Genes in the cellular component class were mostly associated with cell part and organelle part, while those in biological process and molecular function classes were mainly associated with cell process, biological regulation, and binding, and catalytic activity, respectively. Overall, this review highlights the paucity of research on cancer genomics on African populations, identified gaps, and discussed the need for concerted efforts to encourage more research on cancer genomics in Africa.
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Affiliation(s)
- Solomon O Rotimi
- Department of Translational Genomics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Oluwakemi A Rotimi
- Department of Translational Genomics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Bodour Salhia
- Department of Translational Genomics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,Norris Comprehensive Cancer Centre, University of Southern California, Los Angeles, CA, United States
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6
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Mighri N, Hamdi Y, Boujemaa M, Othman H, Ben Nasr S, El Benna H, Mejri N, Labidi S, Ayari J, Jaidene O, Bouaziz H, Ben Rekaya M, M'rad R, Haddaoui A, Rahal K, Boussen H, Boubaker S, Abdelhak S. Identification of Novel BRCA1 and RAD50 Mutations Associated With Breast Cancer Predisposition in Tunisian Patients. Front Genet 2020; 11:552971. [PMID: 33240314 PMCID: PMC7677579 DOI: 10.3389/fgene.2020.552971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 10/16/2020] [Indexed: 12/12/2022] Open
Abstract
Background Deleterious mutations on BRCA1/2 genes are known to confer high risk of developing breast and ovarian cancers. The identification of these mutations not only helped in selecting high risk individuals that need appropriate prevention approaches but also led to the development of the PARP-inhibitors targeted therapy. This study aims to assess the prevalence of the most frequent BRCA1 mutation in Tunisia, c.211dupA, and provide evidence of its common origin as well as its clinicopathological characteristics. We also aimed to identify additional actionable variants using classical and next generation sequencing technologies (NGS) which would allow to implement cost-effective genetic testing in limited resource countries. Patients and Methods Using sanger sequencing, 112 breast cancer families were screened for c.211dupA. A set of patients that do not carry this mutation were investigated using NGS. Haplotype analysis was performed to assess the founder effect and to estimate the age of this mutation. Correlations between genetic and clinical data were also performed. Results The c.211dupA mutation was identified in 8 carriers and a novel private BRCA1 mutation, c.2418dupA, was identified in one carrier. Both mutations are likely specific to North-Eastern Tunisia. Haplotype analysis supported the founder effect of c.211dupA and showed its recent origin. Phenotype-genotype correlation showed that both BRCA1 mutations seem to be associated with a severe phenotype. Whole Exome Sequencing (WES) analysis of a BRCA negative family revealed a Variant of Unknown Significance, c.3647C > G on RAD50. Molecular modeling showed that this variant could be classified as deleterious as it is responsible for destabilizing the RAD50 protein structure. Variant prioritization and pathway analysis of the WES data showed additional interesting candidate genes including MITF and ANKS6. Conclusion We recommend the prioritization of BRCA1-c.211dupA screening in high risk breast cancer families originating from the North-East of Tunisia. We also highlighted the importance of NGS in detecting novel mutations, such as RAD50-c.3647C > G. In addition, we strongly recommend using data from different ethnic groups to review the pathogenicity of this variant and reconsider its classification in ClinVar.
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Affiliation(s)
- Najah Mighri
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Yosr Hamdi
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Maroua Boujemaa
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Houcemeddine Othman
- Sydney Brenner Institute for Molecular Bioscience, University of the Witwatersrand, Johannesburg, South Africa
| | - Sonia Ben Nasr
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia.,The Military Hospital of Tunis, Department of Medical Oncology, Tunis, Tunisia
| | - Houda El Benna
- Department of Medical Oncology, Abderrahmane Mami Hospital, Ariana, Tunisia
| | - Nesrine Mejri
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia.,Department of Medical Oncology, Abderrahmane Mami Hospital, Ariana, Tunisia
| | - Soumaya Labidi
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia.,Department of Medical Oncology, Abderrahmane Mami Hospital, Ariana, Tunisia
| | - Jihen Ayari
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia.,The Military Hospital of Tunis, Department of Medical Oncology, Tunis, Tunisia
| | - Olfa Jaidene
- Department of Carcinological Surgery, Salah Azaiez Institute, Tunis, Tunisia
| | - Hanen Bouaziz
- Department of Carcinological Surgery, Salah Azaiez Institute, Tunis, Tunisia
| | - Mariem Ben Rekaya
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Ridha M'rad
- Service des Maladies Congénitales et Héréditaires, Hôpital Charles Nicolle, Tunis, Tunisia
| | - Abderrazek Haddaoui
- The Military Hospital of Tunis, Department of Medical Oncology, Tunis, Tunisia
| | - Khaled Rahal
- Department of Carcinological Surgery, Salah Azaiez Institute, Tunis, Tunisia
| | - Hamouda Boussen
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia.,Department of Medical Oncology, Abderrahmane Mami Hospital, Ariana, Tunisia
| | - Samir Boubaker
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics and Oncogenetics, LR16IPT05, Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
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7
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Patterns and Prevalence of Germline BRCA1 and BRCA2 Mutations among High-Risk Breast Cancer Patients in Jordan: A Study of 500 Patients. JOURNAL OF ONCOLOGY 2020; 2020:8362179. [PMID: 32733560 PMCID: PMC7376431 DOI: 10.1155/2020/8362179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 06/22/2020] [Indexed: 12/21/2022]
Abstract
Purpose Knowledge of BRCA1 and BRCA2 mutations has a significant clinical impact on the management and prevention of breast cancer. In this study, we evaluate the pattern and prevalence of germline mutations in BRCA1 and BRCA2 among high-risk Jordanian breast cancer patients selected as per international guidelines. Methods BRCA1 and BRCA2 testing were performed at a reference genetic lab. Mutations were classified as pathogenic/likely pathogenic and variant of uncertain significance (VUS). Results A total of 517 patients, median age: 39 (range: 19–78) years, were enrolled. Among the whole group, 72 (13.9%) patients had pathogenic or likely pathogenic BRCA1 (n = 24, 4.6%) or BRCA2 (n = 48, 9.3%) mutations, while 53 (10.3%) others had VUS. Among 333 younger (≤40 years) patients, mutations were observed in 44 (13.2%). Positive mutations were found in 40 (16.5%) patients with one or more close relatives with breast cancer and in 20 (35.1%) of the 57 patients with triple-negative disease. Multivariate analysis showed that a triple-negative status, history of two or more close relatives with breast cancer, and history of one or more close relatives with invasive ovarian cancer were associated with significant high odds ratios (OR) of carrying a pathogenic variant, with an OR (95% CI) of 5.08 (2.66–9.67), 3.24 (1.78–5.89), and 2.97 (1.04–8.52), respectively. Conclusions BRCA1 and BRCA2 mutations are not uncommon among Jordanian patients. Young age has the weakest association with positive mutations, while patients with triple-negative disease, especially those with an additional positive family history, have the highest mutation rate.
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8
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Ouni N, Ben Chaaben A, Ayari F, Douik H, Guizani I, Benammar-Elgaaied A, Guemira F, Tamouza R. MICA-129 Met/Val polymorphism could be a genetic biomarker for Familial Breast Cancer in the Tunisian population. Int J Immunogenet 2020; 47:406-413. [PMID: 32048423 DOI: 10.1111/iji.12480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/05/2020] [Accepted: 01/20/2020] [Indexed: 12/12/2022]
Abstract
Identification of candidate genes associated with susceptibility of breast cancer can have a significant impact at a cancer management national healthcare systems level, making genetic testing more affordable and cost-effective. We have previously shown that the major histocompatibility complex class I-related chain A (MICA) was related to breast cancer and plays an important role in modulating immune response mechanisms through NKG2D receptor activation. Compared to our previous study, in this work, we recruited a new cohort composed of 354 unrelated Tunisian women affected by breast cancer and 380 age-matched women as controls, all genotyped for MICA-129 Met/Val (rs 1051792). Subsequently, we exanimated the distribution of this polymorphism in ten families. As a result, an association was found between the Val allele and Val/Val genotype and the risk of breast cancer (p = 2.5 × 10-15 ; OR = 2.40; p = 6.5 × 10-13 ; OR = 3.03, respectively). Stratified analysis with age and family history of cancer revealed an association between the Val/Val genotype and younger patients <40 years (p = .003; OR = 2.03). Among those patients having a family history of cancer, 68% had a Val/Val genotype (p = .02; OR = 1.82). In the family study, an analyse of pedigrees revealed that the majority of families showed the development of breast cancer at a young age. Moreover, all patients diagnosed with early-onset breast cancer had a Val/Val genotype. Our results lead us to propose that this polymorphism may be an inherited genetic biomarker contributing to an increased breast cancer risk in Tunisian women.
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Affiliation(s)
- Nesrine Ouni
- Clinical Biology Department, Salah Azaiz Institut, Tunis, Tunisia.,Faculty of Mathematics, Physics and Natural Sciences, University of Tunis El Manar, Tunis, Tunisia
| | - Arij Ben Chaaben
- Clinical Biology Department, Salah Azaiz Institut, Tunis, Tunisia
| | - Fayza Ayari
- Clinical Biology Department, Salah Azaiz Institut, Tunis, Tunisia.,Faculty of Mathematics, Physics and Natural Sciences, University of Tunis El Manar, Tunis, Tunisia
| | - Hayet Douik
- Clinical Biology Department, Salah Azaiz Institut, Tunis, Tunisia
| | - Imen Guizani
- Faculty of Mathematics, Physics and Natural Sciences, University of Tunis El Manar, Tunis, Tunisia.,Faculty of Medicine of Tunis, CHU la Rabta, Laboratory of Biochemistry, Tunis, Tunisia
| | - Amel Benammar-Elgaaied
- Immunology Department, Faculty of Mathematics, Physics, and Natural Sciences, Tunis El Manar University, Tunis, Tunisia
| | - Fethi Guemira
- Clinical Biology Department, Salah Azaiz Institut, Tunis, Tunisia
| | - Ryad Tamouza
- INSERM U955, Translational Psychiatry, Creteil, France.,Fondation FondaMental, Creteil, France.,Department of Psychiatry, AP-HP, DHU PePSY, Hôpital Henri Mondor, Université Paris-Est-Creteil, Creteil, France
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9
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Belaiba F, Medimegh I, Bidet Y, Boussetta S, Baroudi O, Mezlini A, Bignon YJ, Benammar El gaaied A. BRCA1/BRCA2 Mutations Shaped by Ancient Consanguinity Practice in Southern Mediterranean Populations. Asian Pac J Cancer Prev 2018; 19:2963-2972. [PMID: 30362333 PMCID: PMC6291031 DOI: 10.22034/apjcp.2018.19.10.2963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The aim of this study is to investigate the involvement of consanguinity on BRCA1/2 mutation incidence in Southern Mediterranean populations and to confirm their low penetrance by comparison of their recurrence in sporadic and familial breast cancer in a context of ancient consanguinity practice. Our study comprises of two parts: First, a comparison of the consanguinity rates of the South Mediterranean countries in a relationship with the frequency of BRCA1 deleterious mutations in breast cancer families and the recurrence of these mutations. Second, we investigated 23patients with a family history of breast cancer, 51 patients without a family history of breast cancer using next-generation sequencing of BRCA2 and then confirmed by Sanger sequencing for the novel mutation. As results, we clearly show a strong relationship between the frequency of BRCA1 deleterious mutations in breast cancer families and rate of consanguinity, since they are significantly inversely correlated. Four deleterious mutations were found in BRCA2 gene including a novel frame-shift mutationc.9382_9383dup in a patient with familial breast cancer and three other frame-shift mutations c.6591_6592del, c.1310_1313del and c.7654dup in patients with sporadic breast cancer.These results are discussed in a context of selective pressure of ancient consanguinity practice. In conclusion, the study of BRCA1/2 gene in Southern Mediterranean countries revealed low penetrance recurrent mutations in sporadic and familial breast cancer. These mutations have been selected in a context of ancient consanguinity practice along with protective genetic and environmental factors.
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Affiliation(s)
- Fadoua Belaiba
- Laboratory of Genetics, Immunology and Human Pathology, Faculty of Sciences of Tunis, Université de Tunis El Manar, Campus universitaire1060 El Manar I Tunis, Tunisia.
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10
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Elloumi-Zghal H, Chaabouni Bouhamed H. Genetics and genomic medicine in Tunisia. Mol Genet Genomic Med 2018; 6:134-159. [PMID: 29663716 PMCID: PMC5902400 DOI: 10.1002/mgg3.392] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 01/19/2023] Open
Abstract
Genetics and genomic medicine in Tunisia.
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11
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Abdel-Razeq H, Al-Omari A, Zahran F, Arun B. Germline BRCA1/BRCA2 mutations among high risk breast cancer patients in Jordan. BMC Cancer 2018; 18:152. [PMID: 29409476 PMCID: PMC5802063 DOI: 10.1186/s12885-018-4079-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 01/29/2018] [Indexed: 11/10/2022] Open
Abstract
Background Breast cancer is the most common malignancy and the leading cause of cancer-related deaths among Jordanian women. With a median age of 50 years at diagnosis, a higher prevalence of hereditary breast cancer may be expected. The objective of this pilot study is to evaluate, for the first time, the contribution of germline mutations in BRCA1/2 to breast cancer among Jordanian patients. Methods Jordanian breast cancer women with a selected high risk profile were invited to participate. Peripheral blood samples were obtained for DNA extraction. A detailed 3-generation family history was also collected. BRCA sequencing was performed at a reference laboratory. Mutations were classified as deleterious, suspected deleterious, variant of uncertain significance or favor polymorphisms. Patients’ medical records were reviewed for extraction of clinical and tumor pathology data. Results One hundred patients were enrolled to the study. Median age was 40 (22–75) years. In total, 20 patients had deleterious and 7 suspected deleterious mutations in BRCA1 or BRCA2 genes. Seven variants of uncertain significance were also detected. After excluding patients tested subsequent to the index case in their families, highest mutation rates were observed among triple negatives (9/16, 56.3%) especially among those with positive family history of breast and/or ovarian cancer (9/13, 69.2%), patients with bilateral or second primary breast cancer (10/15, 66.7%) and those with family history of male breast cancer (2/5, 40.0%). Conclusions BRCA1/2 mutations are not uncommon among selected Jordanian females with breast cancer. The contribution of these findings to much younger age at diagnosis is debatable. Although small, our selected patient cohort shows an important incidence of deleterious and suspected deleterious BRCA1/2 mutations suggesting that genetic testing should be offered to patients with certain high risk features.
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Affiliation(s)
- Hikmat Abdel-Razeq
- Department of Internal Medicine, King Hussein Cancer Center and University of Jordan, School of Medicine, 202 Queen Rania Al-Abdulla St., P.O. Box 1269 Al-Jubeiha, Amman, 11941, Jordan.
| | - Amal Al-Omari
- Office of Scientific Affairs and Research, King Hussein Cancer Center, 202 Queen Rania Al-Abdulla St., P.O. Box 1269 Al-Jubeiha, Amman, 11941, Jordan
| | - Farah Zahran
- Office of Scientific Affairs and Research, King Hussein Cancer Center, 202 Queen Rania Al-Abdulla St., P.O. Box 1269 Al-Jubeiha, Amman, 11941, Jordan
| | - Banu Arun
- Department of Breast Medical Oncology, University of Texas, M D Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA
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12
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A novel BRCA2 in frame deletion in a Tunisian woman with early onset sporadic breast cancer. ACTA ACUST UNITED AC 2015; 63:185-9. [PMID: 26320393 DOI: 10.1016/j.patbio.2015.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/23/2015] [Indexed: 01/11/2023]
Abstract
BACKGROUND Breast cancer is increasing among young women in Tunisia. Germline mutations in the BRCA1/2 genes are associated with a high risk for breast cancer development. However, the true contribution of BRCA1/2 mutation in sporadic breast cancer is not well documented. Our aim is to identify the BRCA2 mutation spectrum in Tunisian young women with breast cancer. METHODS Screening the BRCA2 gene was performed using DHPLC, DNA sequencing and PCR-RFLP. RESULTS We identified, in a woman diagnosed with early onset breast cancer, and without family history, a novel in frame deletion 5456delGTAGCA in the exon 11 of the BRCA2 gene which causes a loss of two residues Ser1743-Ser1744. The absence of this deletion in the patients' parents suggests that it is a de novo variant. Furthermore, we screened 108 sporadic cases, 50 familial cases, and 60 controls for the identified del6bp using PCR-RFLP. None of them carried this deletion suggesting that this variant is not a benign polymorphism and probably rare in our population. With regards to the position of the Ser1743-1744 in the BRCT domain, sequence alignment revealed that the Ser1743 is conserved among several species, which may reflect its importance in the BRCA2 function. A modeling of the wild-type and mutated BRC5-BRC6 domain revealed that the deletion of the 2 Serine residues might affect the structure of this BRCA2 domain. CONCLUSIONS A novel in frame deletion 5456del6bp in BRCA2 gene was identified in an early onset woman with breast cancer and without family history.
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13
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Tadmouri GO, Sastry KS, Chouchane L. Arab gene geography: From population diversities to personalized medical genomics. Glob Cardiol Sci Pract 2014; 2014:394-408. [PMID: 25780794 PMCID: PMC4355514 DOI: 10.5339/gcsp.2014.54] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 12/11/2014] [Indexed: 12/20/2022] Open
Abstract
Genetic disorders are not equally distributed over the geography of the Arab region. While a number of disorders have a wide geographical presence encompassing 10 or more Arab countries, almost half of these disorders occur in a single Arab country or population. Nearly, one-third of the genetic disorders in Arabs result from congenital malformations and chromosomal abnormalities, which are also responsible for a significant proportion of neonatal and perinatal deaths in Arab populations. Strikingly, about two-thirds of these diseases in Arab patients follow an autosomal recessive mode of inheritance. High fertility rates together with increased consanguineous marriages, generally noticed in Arab populations, tend to increase the rates of genetic and congenital abnormalities. Many of the nearly 500 genes studied in Arab people revealed striking spectra of heterogeneity with many novel and rare mutations causing large arrays of clinical outcomes. In this review we provided an overview of Arab gene geography, and various genetic abnormalities in Arab populations, including disorders of blood, metabolic, circulatory and neoplasm, and also discussed their associated molecules or genes responsible for the cause of these disorders. Although studying Arab-specific genetic disorders resulted in a high value knowledge base, approximately 35% of genetic diseases in Arabs do not have a defined molecular etiology. This is a clear indication that comprehensive research is required in this area to understand the molecular pathologies causing diseases in Arab populations.
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Affiliation(s)
| | - Konduru S Sastry
- Laboratory of Genetic Medicine and Immunology, Weill Cornell Medical College in Qatar, Qatar Foundation, Doha, Qatar
| | - Lotfi Chouchane
- Laboratory of Genetic Medicine and Immunology, Weill Cornell Medical College in Qatar, Qatar Foundation, Doha, Qatar
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14
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Medimegh I, Troudi W, Stambouli N, Khodjet-El-Khil H, Baroudi O, Ayari H, Omrane I, Uhrhammer N, Privat M, Mezlini A, Ayed FB, Romdhane KB, Mader S, Bignon YJ, Elgaaied AB. Wild-type genotypes of BRCA1 gene SNPs combined with micro-RNA over-expression in mammary tissue leading to familial breast cancer with an increased risk of distant metastases’ occurrence. Med Oncol 2014; 31:255. [DOI: 10.1007/s12032-014-0255-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 09/18/2014] [Indexed: 11/28/2022]
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15
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Chouchane L, Boussen H, Sastry KSR. Breast cancer in Arab populations: molecular characteristics and disease management implications. Lancet Oncol 2013; 14:e417-24. [PMID: 23993386 DOI: 10.1016/s1470-2045(13)70165-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Breast cancer is a major health problem in both developing and developed countries. It is the most frequently diagnosed female malignant disease in Arab populations. The incidence of breast cancer is lower in Arab countries than in Europe and the USA but is rising fast. Breast cancers in women from Arab populations have different characteristics to those reported in individuals from Europe and the USA. For example, affected patients are at least a decade younger, they have a more advanced stage of disease at first presentation, and their tumour size is larger. Moreover, in some Arab populations, reports suggest increased axillary-lymph-node invasion, a larger proportion of negative hormone receptors, and a higher tumour grade. These disparities are not only confined to clinicopathological features but also exist at the molecular level, as shown by findings of genome-wide association studies and expression profiling.
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Affiliation(s)
- Lotfi Chouchane
- Laboratory of Genetic Medicine and Immunology, Weill Cornell Medical College in Qatar, Qatar Foundation, Doha, Qatar.
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16
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Karami F, Mehdipour P. A comprehensive focus on global spectrum of BRCA1 and BRCA2 mutations in breast cancer. BIOMED RESEARCH INTERNATIONAL 2013; 2013:928562. [PMID: 24312913 PMCID: PMC3838820 DOI: 10.1155/2013/928562] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/31/2013] [Accepted: 08/15/2013] [Indexed: 02/05/2023]
Abstract
Breast cancer (BC) is the most common cancer of women all over the world. BRCA1 and BRCA2 gene mutations comprise the most important genetic susceptibility of BC. Except for few common mutations, the spectrum of BRCA1 and BRCA2 mutations is heterogeneous in diverse populations. 185AGdel and 5382insC are the most important BRCA1 and BRCA2 alterations which have been encountered in most of the populations. After those Ashkenazi founder mutations, 300T>G also demonstrated sparse frequency in African American and European populations. This review affords quick access to the most frequent alterations among various populations which could be helpful in BRCA screening programs.
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Affiliation(s)
- Fatemeh Karami
- Department of Medical Genetics, Tehran University of Medical Sciences, School of Medicine, Tehran, Iran
| | - Parvin Mehdipour
- Department of Medical Genetics, Tehran University of Medical Sciences, School of Medicine, Tehran, Iran
- *Parvin Mehdipour:
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17
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Romdhane L, Kefi R, Azaiez H, Ben Halim N, Dellagi K, Abdelhak S. Founder mutations in Tunisia: implications for diagnosis in North Africa and Middle East. Orphanet J Rare Dis 2012; 7:52. [PMID: 22908982 PMCID: PMC3495028 DOI: 10.1186/1750-1172-7-52] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 08/02/2012] [Indexed: 01/17/2023] Open
Abstract
Background Tunisia is a North African country of 10 million inhabitants. The native background population is Berber. However, throughout its history, Tunisia has been the site of invasions and migratory waves of allogenic populations and ethnic groups such as Phoenicians, Romans, Vandals, Arabs, Ottomans and French. Like neighbouring and Middle Eastern countries, the Tunisian population shows a relatively high rate of consanguinity and endogamy that favor expression of recessive genetic disorders at relatively high rates. Many factors could contribute to the recurrence of monogenic morbid trait expression. Among them, founder mutations that arise in one ancestral individual and diffuse through generations in isolated communities. Method We report here on founder mutations in the Tunisian population by a systematic review of all available data from PubMed, other sources of the scientific literature as well as unpublished data from our research laboratory. Results We identified two different classes of founder mutations. The first includes founder mutations so far reported only among Tunisians that are responsible for 30 genetic diseases. The second group represents founder haplotypes described in 51 inherited conditions that occur among Tunisians and are also shared with other North African and Middle Eastern countries. Several heavily disabilitating diseases are caused by recessive founder mutations. They include, among others, neuromuscular diseases such as congenital muscular dystrophy and spastic paraglegia and also severe genodermatoses such as dystrophic epidermolysis bullosa and xeroderma pigmentosa. Conclusion This report provides informations on founder mutations for 73 genetic diseases either specific to Tunisians or shared by other populations. Taking into account the relatively high number and frequency of genetic diseases in the region and the limited resources, screening for these founder mutations should provide a rapid and cost effective tool for molecular diagnosis. Indeed, our report should help designing appropriate measures for carrier screening, better evaluation of diseases burden and setting up of preventive measures at the regional level.
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Affiliation(s)
- Lilia Romdhane
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de Tunis, BP 74, 13 Place Pasteur, Tunis 1002, Tunisia
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18
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Contribution of epigenetic alteration of BRCA1 and BRCA2 genes in breast carcinomas in Tunisian patients. Cancer Epidemiol 2012; 36:190-7. [DOI: 10.1016/j.canep.2011.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 08/28/2011] [Accepted: 09/04/2011] [Indexed: 12/31/2022]
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19
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Mahfoudh W, Bouaouina N, Ahmed SB, Gabbouj S, Shan J, Mathew R, Uhrhammer N, Bignon YJ, Troudi W, Elgaaied ABA, Hassen E, Chouchane L. Hereditary breast cancer in Middle Eastern and North African (MENA) populations: identification of novel, recurrent and founder BRCA1 mutations in the Tunisian population. Mol Biol Rep 2011; 39:1037-46. [PMID: 21603858 PMCID: PMC3249560 DOI: 10.1007/s11033-011-0829-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 05/03/2011] [Indexed: 01/20/2023]
Abstract
Germ-line mutations in BRCA1 breast cancer susceptibility gene account for a large proportion of hereditary breast cancer families and show considerable ethnic and geographical variations. The contribution of BRCA1 mutations to hereditary breast cancer has not yet been thoroughly investigated in Middle Eastern and North African populations. In this study, 16 Tunisian high-risk breast cancer families were screened for germline mutations in the entire BRCA1 coding region and exon-intron boundaries using direct sequencing. Six families were found to carry BRCA1 mutations with a prevalence of 37.5%. Four different deleterious mutations were detected. Three truncating mutations were previously described: c.798_799delTT (916 delTT), c.3331_3334delCAAG (3450 delCAAG), c.5266dupC (5382 insC) and one splice site mutation which seems to be specific to the Tunisian population: c.212 + 2insG (IVS5 + 2insG). We also identified 15 variants of unknown clinical significance. The c.798_799delTT mutation occurred at an 18% frequency and was shared by three apparently unrelated families. Analyzing five microsatellite markers in and flanking the BRCA1 locus showed a common haplotype associated with this mutation. This suggests that the c.798_799delTT mutation is a Tunisian founder mutation. Our findings indicate that the Tunisian population has a spectrum of prevalent BRCA1 mutations, some of which appear as recurrent and founding mutations.
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Affiliation(s)
- Wijden Mahfoudh
- Department of Molecular Immuno-Oncology, Faculty of Medicine, 5019 Monastir, Tunisia
| | - Noureddine Bouaouina
- Department of Molecular Immuno-Oncology, Faculty of Medicine, 5019 Monastir, Tunisia
- Department of Radiation Oncology, CHU Farhat Hached, 4000 Sousse, Tunisia
| | - Slim Ben Ahmed
- Department of Medical Oncology, CHU Farhat Hached, 4000 Sousse, Tunisia
| | - Sallouha Gabbouj
- Department of Molecular Immuno-Oncology, Faculty of Medicine, 5019 Monastir, Tunisia
| | - Jingxuan Shan
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, P.O. Box 24144, Doha, Qatar
| | - Rebecca Mathew
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, P.O. Box 24144, Doha, Qatar
| | - Nancy Uhrhammer
- Laboratoire Diagnostic Génétique et Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France
| | - Yves-Jean Bignon
- Laboratoire Diagnostic Génétique et Moléculaire, Centre Jean Perrin, Clermont-Ferrand, France
| | - Wafa Troudi
- Laboratory of Genetics, Immunology and Human Pathology at the Faculty of Sciences of Tunis, University El Manar I, 1060 Tunis, Tunisia
| | - Amel Ben Ammar Elgaaied
- Laboratory of Genetics, Immunology and Human Pathology at the Faculty of Sciences of Tunis, University El Manar I, 1060 Tunis, Tunisia
| | - Elham Hassen
- Department of Molecular Immuno-Oncology, Faculty of Medicine, 5019 Monastir, Tunisia
| | - Lotfi Chouchane
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, P.O. Box 24144, Doha, Qatar
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Germline mutations in BRCA1 and BRCA2 genes in ethnically diverse high risk families in Israel. Breast Cancer Res Treat 2010; 127:489-95. [PMID: 20960228 DOI: 10.1007/s10549-010-1217-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Accepted: 10/05/2010] [Indexed: 10/18/2022]
Abstract
Three mutations in BRCA1 (185delAG, 5382InsC) and BRCA2 (6174delT) predominate among high risk breast ovarian cancer Ashkenazi Jewish families, with few "private" mutations described. Additionally, the spectrum of BRCA1 and BRCA2 germline mutations among high risk Jewish non Ashkenazi and non Jewish Israelis is undetermined. Genotyping by exon-specific sequencing or heteroduplex analysis using enhanced mismatch mutation analysis was applied to 250 high risk, predominantly cancer affected, unrelated Israeli women of Ashkenazi (n = 72), non Ashkenazi (n = 90), Moslem (n = 45), Christian Arabs (n = 21), Druze (n = 17), and non Jewish Caucasians (n = 5). All Jewish women were prescreened and did not harbor any of the predominant BRCA1 or BRCA2 Jewish mutations. Age at diagnosis of breast cancer (median ± SD) (n = 219) was 40.1 ± 11.7, 45.6 ± 10.7, 38.7 ± 9.2, 45.5 ± 11.4 ± and 40.7 ± 8.1 years for Ashkenazi, non Ashkenazi, Moslem, Christian, and Druze participants, respectively. For ovarian cancer (n = 19) the mean ages were 45.75 ± 8.2, 57.9 ± 10.1, 54 ± 8, 70 ± 0, and 72 ± 0 for these origins, respectively. Overall, 22 (8.8%) participants carried 19 clearly pathogenic mutations-10 BRCA1 and 9 BRCA2 (3 novel): 3 in Ashkenazim, 6 in 8 non-Ashkenazim, 6 in 7 Moslems, 2 in Druze, and 2 in non Jewish Caucasians. Only three mutations (c.1991del4, C61G, A1708E) were detected in 2 seemingly unrelated families of Moslem and non- Ashkenazi origins. There were no inactivating mutations among 55 Ashkenazi high risk breast cancer only families. In conclusion, there are no predominant recurring germline mutations in BRCA1 or BRCA2 genes among ethnically diverse Jewish and non Jewish high risk families in Israel.
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Yacoubi Loueslati B, Troudi W, Cherni L, Rhomdhane KB, Mota-Vieira L. Germline HVR-II mitochondrial polymorphisms associated with breast cancer in Tunisian women. GENETICS AND MOLECULAR RESEARCH 2010; 9:1690-700. [PMID: 20812191 DOI: 10.4238/vol9-3gmr778] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A high incidence of somatic mtDNA polymorphisms has been reported in a wide variety of human cancers; some of them have been proposed as markers for the early detection of breast cancer. However, little attention has been paid to the potential of germline mitochondrial sequence variations as genetic risk factors for cancer. We performed a case-control study of 70 unrelated Tunisian women with breast cancer and 80 healthy age- and gender-matched blood donors, taking into account clinicopathological data, to evaluate germline polymorphism of mitochondrial HVR-II region as a genetic risk factor for breast cancer. Through direct sequencing, we detected 351 polymorphisms in controls and 248 variants in patients, with 47 and 39 segregating sites, respectively. In both groups, more than 50% of the polymorphisms were due to four variants: 315 ins C, 309 ins C, 263 A>G, and 73 A>G. The HVR-II sequences were also classified into haplotypes on the basis of the polymorphisms. Fifty-nine different haplotypes were found, 20 of them shared between patients and controls. Both groups had specific haplotypes, 18 in breast cancer patients and 21 in controls. Statistical analysis revealed a weak protective effect against breast cancer risk for two mitochondrial polymorphisms - 152 T>C (odds ratio (OR) = 0.33, 95% confidence interval (CI) = 0.12-0.91) and 263 A>G (OR = 0.17, 95%CI = 0.06-0.47). In contrast, an increased risk of breast cancer was detected for the 315+C haplotype (OR = 11.66, 95%CI = 1.44-252.23). We conclude that mitochondrial variants can affect breast cancer risk. More extensive studies, involving different types of cancer and patients with different genetic makeup, will be required to improve our understanding of the effects of germline mtDNA polymorphisms on carcinogenesis.
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Affiliation(s)
- B Yacoubi Loueslati
- Department of Biology, Faculty of Sciences of Tunis, ElManar University, Tunis, Tunisia.
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