Yeast Genetics and Genomics, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology, CNR via Moruzzi 1, 56125 Pisa, Italy.
Division of Internal Medicine, University Hospital of Pisa, 56125 Pisa, Italy.
Int J Mol Sci. 2022 Apr 6;23(7):4049. doi: 10.3390/ijms23074049.
Germline mutations in the BRCA1 gene have been reported to increase the lifetime risk of developing breast and/or ovarian cancer (BOC). By new sequencing technologies, numerous variants of uncertain significance (VUS) are identified. It is mandatory to develop new tools to evaluate their functional impact and pathogenicity. As the expression of pathogenic BRCA1 variants in increases the frequency of intra- and inter-chromosomal homologous recombination (HR), and gene reversion (GR), we validated the two HR and the GR assays by testing 23 benign and 23 pathogenic variants and compared the results with those that were obtained in the small colony phenotype (SCP) assay, an additional yeast-based assay, that was validated previously. We demonstrated that they scored high accuracy, sensitivity, and sensibility. By using a classifier that was based on majority of voting, we have integrated data from HR, GR, and SCP assays and developed a reliable method, named yBRCA1, with high sensitivity to obtain an accurate VUS functional classification (benign or pathogenic). The classification of BRCA1 variants, important for assessing the risk of developing BOC, is often difficult to establish with genetic methods because they occur rarely in the population. This study provides a new tool to get insights on the functional impact of the BRCA1 variants.
BRCA1 基因种系突变已被报道会增加个体终生罹患乳腺癌和/或卵巢癌（BOC）的风险。通过新一代测序技术，大量意义未明的变异（VUS）被鉴定出来。因此，开发新的工具来评估它们的功能影响和致病性是非常必要的。由于致病性 BRCA1 变异的表达增加了染色体内和染色体间同源重组（HR）以及基因回复（GR）的频率，我们通过测试 23 种良性和 23 种致病性变异来验证这两种 HR 和 GR 检测方法，并将结果与先前验证过的基于酵母的小菌落表型（SCP）检测方法的结果进行了比较。我们证明了这些方法具有较高的准确性、灵敏度和特异性。通过使用基于多数投票的分类器，我们整合了 HR、GR 和 SCP 检测方法的数据，并开发了一种名为 yBRCA1 的可靠方法，该方法具有较高的灵敏度，可以对 VUS 进行准确的功能分类（良性或致病性）。对 BRCA1 变异的分类对于评估罹患 BOC 的风险非常重要，但由于它们在人群中很少发生，因此用遗传方法进行分类通常具有挑战性。本研究为评估 BRCA1 变异的功能影响提供了一种新的工具。
