Laboratório de Medicina Genômica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS Brazil.
Genet Mol Biol. 2009 Jul;32(3):437-46. doi: 10.1590/S1415-47572009005000049. Epub 2009 Sep 1.
Women with mutations in the breast cancer genes BRCA1 or BRCA2 have an increased lifetime risk of developing breast, ovarian and other BRCA-associated cancers. However, the number of detected germline mutations in families with hereditary breast and ovarian cancer (HBOC) syndrome is lower than expected based upon genetic linkage data. Undetected deleterious mutations in the BRCA genes in some high-risk families are due to the presence of intragenic rearrangements such as deletions, duplications or insertions that span whole exons. This article reviews the molecular aspects of BRCA1 and BRCA2 rearrangements and their frequency among different populations. An overview of the techniques used to screen for large rearrangements in BRCA1 and BRCA2 is also presented. The detection of rearrangements in BRCA genes, especially BRCA1, offers a promising outlook for mutation screening in clinical practice, particularly in HBOC families that test negative for a germline mutation assessed by traditional methods.
携带有乳腺癌基因 BRCA1 或 BRCA2 突变的女性,其一生中罹患乳腺癌、卵巢癌和其他与 BRCA 相关癌症的风险增加。然而,遗传性乳腺癌和卵巢癌(HBOC)综合征家族中检测到的种系突变数量低于基于遗传连锁数据的预期。在一些高风险家族中,BRCA 基因中未检测到的有害突变是由于存在大片段缺失、重复或插入等基因内重排,这些重排跨越整个外显子。本文综述了 BRCA1 和 BRCA2 重排的分子特征及其在不同人群中的频率。还概述了用于筛查 BRCA1 和 BRCA2 中大片段重排的技术。BRCA 基因重排的检测,特别是 BRCA1,为临床实践中的突变筛查提供了有希望的前景,特别是在通过传统方法评估种系突变呈阴性的 HBOC 家族中。