临床信息：受检者，女，35岁，乳腺癌患者。
检测项目：遗传性乳腺癌-卵巢癌综合征（BRCA1/2全外）检测
检测结果：受检者携带BRCA1基因：NM_007294.3:c.3704delA杂合变异，与遗传性乳腺癌-卵巢癌综合征相关。
变异评级：
c.3704delA变异评级：致病
编码提前终止密码子的序列变异，即BRCA1第1855位氨基酸前发生的移码突变。
变异分级：采用2021年版BRCA1/2数据解读中国专家共识。
BRCA1基因导致的遗传性乳腺癌-卵巢癌综合征呈常染色体显性遗传，外显率约为 39%~68%。BRCA1基因致病变异女性携带者，到70岁时患乳腺癌的累计风险达到 51%~95%，患卵巢癌的累计风险达到22%~60%。
BRCA1/2致病或可能致病的胚系突变患者的直系亲属属于乳腺癌/卵巢癌/胰腺癌（女性）和前列腺/胰腺癌（男性）的高风险人群，建议其进行基因检测筛查。
全球每年有120万女性患乳腺癌，50万女性死于乳腺癌。自20世纪70年代末以来，乳腺癌的发病在全球范围内一直位居女性肿瘤的首位，并且以每年2%的速度递增。
乳腺癌是主要危害妇女身体健康的疾病，男性也可患乳腺癌，但发病率远低于女性。资料表明，近年来我国女性乳腺、卵巢癌的发病正向着年轻化、恶性高的方向发展。据2013年的有关资料表明，乳腺癌的发病率在女性为52/100000，占全身各种恶性肿瘤的7~10%。其发生年龄大多在40~60岁，或绝经期前后的妇女，尤其以45~49岁和60~64岁间发病率最高。
乳腺癌易感基因包括BRCA1和BRCA2。BRCA基因突变会导致基因组不稳定性显著增加，从而显著提高女性罹患乳腺癌、卵巢癌以及其他癌症（如：胰腺癌和前列腺癌等）的风险。
BRCA1/2基因检测为乳腺癌/卵巢癌患者明确致病原因及制定合理的个性化诊疗方案提供参考依据，也可评估健康人群（特别是有乳腺癌/卵巢癌家族史的人群）患卵巢癌、乳腺癌、胰腺癌、前列腺癌等相关肿瘤的风险，为疾病早防早治提供参考依据。
1. 诊断年龄≤40岁的早发性乳腺癌/卵巢癌患者；
2. 有乳腺癌和/或卵巢癌家族史；
3. 双侧乳腺患癌，或者在一侧乳腺或卵巢有多于一个的肿瘤发生部位；
4. 同时患有乳腺癌和卵巢癌；
5. 男性乳腺癌，或有男性近亲患有乳腺癌；
6. 家系中有已知BRCA1/2致病基因存在；
7. 有其他类型肿瘤的患者或家族史：胰腺癌、前列腺癌。
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