Elimam Alsmawal A, Aabdein Mohamed Elmogtba Mouaweia Mohamed, Eldeen Mohamed El-Fatih Moly, Altayb Hisham N, Taha Mohamed Adel, Nimir Mohammed N, Dafaalla Mohamed D, Alfaki Musaab M, Abdelrahim Mohamed A, Abdalla Abdelmohaymin A, Mohammed Musab I, Ellaithi Mona, Hamid Muzamil Mahdi Abdel, Hassan Mohamed Ahmed Salih
Post-graduate College, Al-Neelain University, Khartoum, Sudan.
Daoud Research Group, Khartoum, Sudan.
BMC Med Genet. 2017 Aug 16;18(1):85. doi: 10.1186/s12881-017-0448-x.
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.
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.
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.
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.
乳腺癌（BC）是女性中最常见的癌症类型。在BC的众多风险因素中，发现BRCA2基因突变是5%-10%病例的主要病因。大多数有害突变是移码突变或无义突变。大多数报道的BRCA2突变是蛋白质截短突变。
本研究旨在描述苏丹女性乳腺癌患者中BRCA2（外显子11）基因的突变模式，包括单核苷酸多态性（SNP）和变异。在本研究中，使用聚合酶链反应（PCR）和DNA测序靶向BRCA2外显子11的特定区域。
25/45例（55.6%）早发病例为绝经前女性，平均年龄36.6岁。多产在研究对象中更为常见，共30例（66.6%），平均产次为4.1。在报告的组织学类型中，导管型肿瘤是最主要的类型，有22例（48.8%）。在9例患者中的4例中发现了核苷酸3385处的杂合单等位无义突变，其中TTA密码子转换为终止密码子TGA。
本研究在4例来自不同家庭、被诊断为早发性BC的苏丹女性患者中检测到单等位无义突变。需要进一步开展工作以证明其在BC筛查中的作用。
