Investigation of BRCA1 exon 11 genetic variations in breast cancer among Libyan women (original) (raw)
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Specific BRCA1 gene variations amongst young Moroccan breast cancer patients
Genetics and Molecular Research, 2014
Germline mutations in the BRCA1 gene are known predictive markers for the development of hereditary breast cancer. Nevertheless, no comprehensive study has been performed targeting the presence and relevance of BRCA1 mutations in Moroccan breast cancer patients. We here present an analysis of BRCA1 gene regions (exon 2 and exon 11a/b) of 50 female Moroccan breast cancer patients with early disease onset (≤40 years) or familial disease backgrounds. Results showed that no mutation was present in either exon 2 or exon 11a of the BRCA1 gene in any of the 50 patients analysed. However, in exon 11b, a mutation generated by a nucleotide exchange was detected in 8% of patients, most of whom were young women (≤40). This mutation leads to substitution of the amino acid glutamine by an arginine at position 356 of the polypeptide sequence (Q356R). Although this mutation was previously characterised at a lower frequency in western populations, our study is the first to describe it in a young Moroccan population. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (1): 791-798 (2014) A. Tazzite et al.
Molecular Biology Reports, 2012
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:
BMC Cancer
Background To date, the contribution of BRCA1/2 mutations in Moroccan early onset breast cancer patients remains unknown. Here we assess these genetic alterations for the first time in a cohort from North of Morocco. Methods Thirty-three patients diagnosed with breast cancer at the age of ≤40 years were recruited irrespective of breast and/or ovarian cancer family history. Coding regions and intron-exon boundaries of BRCA1 and BRCA2 genes were sequenced from peripheral blood DNA using Ion Proton (Thermo Fisher Scientific) next generation sequencing platform. Results Overall, five BRCA germline mutations were identified (15.1%). The frequency of mutations among patients with family history of breast cancer was 16.7%. Three mutations were found in BRCA1 (9%) and two within the BRCA2 gene (6%). These are three frameshift mutations (c.798_799del, c.2125_2126insA, c.5116_5119delAATA), one missense (c.116G > A) and one nonsense mutation (c.289G > T). The mutation c.5116_5119delAATA ...
International Journal of Medical Sciences, 2000
Worldwide variation in the distribution of BRCA mutations is well recognised, and for the Moroccan population no comprehensive studies about BRCA mutation spectra or frequencies have been published. We therefore performed mutation analysis of the BRCA1 gene in 121 Moroccan women diagnosed with breast cancer. All cases completed epidemiology and family history questionnaires and provided a DNA sample for BRCA testing. Mutation analysis was performed by direct DNA sequencing of all coding exons and flanking intron sequences of the BRCA1 gene. 31.6 % (6/19) of familial cases and 1 % (1/102) of early-onset sporadic (< 45 years) were found to be associated with BRCA1 mutations. The pathogenic mutations included two frame-shift mutations (c.798_799delTT, c.1016dupA), one missense mutation (c.5095C>T), and one nonsense mutation (c.4942A>T). The c.798_799delTT mutation was also observed in Algerian and Tunisian BC families, suggesting the first non-Jewish founder mutation to be described in Northern Africa. In addition, ten different unclassified variants were detected in BRCA1, none of which were predicted to affect splicing. Most unclassified variants were placed in Align-GVGD classes suggesting neutrality. c.5117G>C involves a highly conserved amino acid suggestive of interfering with function (Align-GVGD class C55), but has been observed in conjunction with a deleterious mutation in a Tunisian family. These findings reflect the genetic heterogeneity of the Moroccan population and are relevant to genetic counselling and clinical management. The role of BRCA2 in BC is also under study.
Journal of Babol University of Medical Sciences, 2018
BACKGROUND AND OBJECTIVE: Breast cancer is the most common cancer in women, which is associated with genetic changes such as mutations in carcinogenic genes and tumor suppressor genes. One of the most important tumor suppressor genes involved in breast cancer is the BRCA1 gene. The mutation in this gene is a common occurrence in human breast cancer. The purpose of this study is to investigate the mutations of exon 11-A of BRCA1 gene in women with breast cancer in the northwest of Iran. METHODS: In this descriptive study, blood sample were collected form 40 patients with breast cancer whose cancer was diagnosed before the age of 40 years and the exon 11-A of BRCA1 gene was examined using PCR and direct sequencing methods to detect mutations. Sequencing results were analyzed using Chromas software. FINDING: In the present study, a nonsynonymous mutation was reported as a new mutation of BRCA1 gene for the first time: Ala584Thr mutation was also observed in two samples. The mutations of codon 694 (Ser694Ser) showed a higher incidence (52.5%). Other mutations were observed in codons 693, 356, 486, 550 and 628. CONCLUSION: Based on the results of this study, mutations and polymorphisms of exon 11 of BRCA1 gene were observed for the first time in the northwestern population of Iran. One new case of mutation was observed in exon 11-A of BRCA1 gene.
BRCA1 and BRCA2 Mutations in Ethnic Lebanese Arab Women With High Hereditary Risk Breast Cancer
Oncologist, 2015
Purpose. Breast cancer is the most common malignancy among women in Lebanon and in Arab countries, with 50% of cases presenting before the age of 50 years. Methods. Between 2009 and 2012, 250 Lebanese women with breastcancer who were considered to be at high riskof carrying BRCA1 or BRCA2 mutations because of presentation at young age and/or positive family history (FH) of breast or ovarian cancer were recruited. Clinical data were analyzed statistically. Coding exons and intron-exon boundaries of BRCA1 and BRCA2 were sequenced from peripheral blood DNA. All patients were tested for BRCA1 rearrangements using multiplex ligationdependent probe amplification (MLPA). BRCA2 MLPA was done in selected cases. Results. Overall, 14 of 250 patients (5.6%) carried a deleterious BRCA mutation (7 BRCA1, 7 BRCA2) and 31 (12.4%) carried a variant of uncertain significance. Eight of 74 patients (10.8%) aged #40 years with positive FH and only 1 of 74 patients (1.4%) aged #40 years without FH had a mutated BRCA. Four of 75 patients (5.3%) aged 41-50 years with FH had a deleterious mutation. Only 1 of 27 patients aged .50 years at diagnosis had a BRCA mutation. All seven patients with BRCA1 mutations had grade 3 infiltrating ductal carcinoma and triple-negative breast cancer. Nine BRCA1 and 17 BRCA2 common haplotypes were observed. Conclusion. Prevalence ofdeleterious BRCA mutations is lower than expected and does not support the hypothesis that BRCA mutations alone cause the observed high percentage of breast cancer in young women of Lebanese and Arab descent. Studies to search for other genetic mutations are recommended.
BRCA1 and BRCA2 Mutations in Ethnic Lebanese Arab Women With High Hereditary Risk Breast Cancer
The oncologist, 2015
Breast cancer is the most common malignancy among women in Lebanon and in Arab countries, with 50% of cases presenting before age 50 years. Between 2009 and 2012, 250 Lebanese women with breast cancer who were considered to be at high risk of carrying BRCA1 or BRCA2 mutations because of presentation at young age and/or positive family history (FH) of breast or ovarian cancer were recruited. Clinical data were analyzed statistically. Coding exons and intron-exon boundaries of BRCA1 and BRCA2 were sequenced from peripheral blood DNA. All patients were tested for BRCA1 rearrangements using multiplex ligation-dependent probe amplification (MLPA). BRCA2 MLPA was done in selected cases. Overall, 14 of 250 patients (5.6%) carried a deleterious BRCA mutation (7 BRCA1, 7 BRCA2) and 31 (12.4%) carried a variant of uncertain significance. Eight of 74 patients (10.8%) aged ≤40 years with positive FH and only 1 of 74 patients (1.4%) aged ≤40 years without FH had a mutated BRCA. Four of 75 patien...
Background: Breast cancer (BC) is the most common type of cancer in women. Among many risk factors of BC, mutations in BRCA2 gene were found to be the primary cause in 5-10% of cases. The majority of deleterious mutations are frameshift or nonsense mutations. Most of the reported BRCA2 mutations are protein truncating mutations. Methods: The study aimed to describe the pattern of mutations including single nucleotide polymorphisms (SNPs) and variants of the BRCA2 (exon11) gene among Sudanese women patients diagnosed with BC. In this study a specific region of BRCA2 exon 11 was targeted using PCR and DNA sequencing. Results: Early onset cases 25/45 (55.6%) were premenopausal women with a mean age of 36.6 years. Multiparity was more frequent within the study amounting to 30 cases (66.6%), with a mean parity of 4.1. Ductal type tumor was the predominant type detected in 22 cases (48.8%) among the reported histotypes. A heterozygous monoallelic nonsense mutation at nucleotide 3385 was found in four patients out of 9, where TTA codon was converted into the stop codon TGA. Conclusion: This study detected a monoallelic nonsense mutation in four Sudanese female patients diagnosed with early onset BC from different families. Further work is needed to demonstrate its usefulness in screening of BC.
Breast Cancer Research and Treatment, 2007
The etiology of breast cancer in Africa is scarcely investigated. Breast cancer was responsible for 456/2,233 cancer patients (20.4%) ascertained between 1999 and 2004 at Gezira University, Central Sudan. Male breast cancer accounted for 16/456 patients (3.5%), 275/440 female patients (62.5%) were premenopausal and 150/440 cases (34%) occurred in women with ≥5 childbirths. We characterized for germline BRCA1/2 mutations a one-year series of patients (34 females, 1 male) selected by diagnosis within age 40 years or male gender. Overall 33/35 patients were found to carry 60 BRCA1/2 variants, of which 17 (28%) were novel, 22 (37%) reported in populations from various geographic areas and 21 (35%) reported worldwide. Detected variants included 5 truncating mutations, one of which (in BRCA2) was in the male patient. The 55 non-truncating variants included 3 unclassified variants predicted to affect protein product and not co-occurring with a truncating mutation in the same gene. Patients were from different tribes but AMOVA showed that most BRCA1/2 variation was within individuals (86.41%) and patients clustered independently of tribe in a phylogenetic tree. Cluster analysis based on age at cancer diagnosis and reproductive variables split female patients in two clusters that, by factor analysis, were explained by low versus high scores of the total period occupied by pregnancies and lactation. The cluster with low scores comprised all 4 patients with truncating mutations and 3 of the 4 carriers of unclassified variants predicted to affect protein product. Our findings suggest that in Central Sudan BRCA1/2 represent an important etiological factor of breast cancer in males and young women less exposed to pregnancy and lactation. Factors other than BRCA1/2 may contribute to breast cancer in young highly multiparous women who breast-fed for prolonged periods.
Breast cancer is the most common cancer in women and its impact on morbidity and mortality is significant and well documented. BRCA genes mutation account for most of the cases of familial breast cancer. Female BRCA1 mutation carriers have an 80% to 85% risk of developing breast cancer over their life-time. This study aims to detect 5382insC ,185delAG and C61G mutations in BRCA1 gene in healthy females and breast cancer female patients in Qalubia Governorate and correlate them with the presence or absence of family history of breast &/ or ovarian cancer to allow identification of individuals at high risk. Materials and methods: 50 females divided into 20 healthy females and 30 breast cancer patients with or without family history of breast &/or ovarian cancers were included in the study.185delAG and 5382insC mutation were detected by multiplex mutagenically separated PCR (MS -PCR) and C61G mutation was detected using the RFLP method. Results: It was found that the incidence of BRCA1 gene mutation in the breast cancer group was higher than its incidence in the control group Also the incidence of BRCA1 gene mutation in the groups with family history was higher than in the groups without family history. In addition, multiple exons mutation frequency was higher than one exon mutation in the breast cancer group with family history .Moreover, 5382insC mutation was found to be the most frequent BRCA 1 gene mutation among the females of Qalubia governorate followed by C61G mutation and 185 delAG mutation. Conclusion: In conclusion, BRCA1 gene mutation and multiple BRCA1 exons mutations play an important role in the pathogenesis of familial breast cancer in Qalubia Governorate, Egypt.