臨床信息：受檢者，女，35歲，乳腺癌患者。
檢測項目：遺傳性乳腺癌-卵巢癌綜合征（BRCA1/2全外）檢測
檢測結果：受檢者攜帶BRCA1基因：NM_007294.3:c.3704delA雜合變異，與遺傳性乳腺癌-卵巢癌綜合征相關。
變異評級：
c.3704delA變異評級：致病
編碼提前終止密碼子的序列變異，即BRCA1第1855位氨基酸前發生的移碼突變。
變異分級：采用2021年版BRCA1/2數據解讀中國專家共識。
BRCA1基因導致的遺傳性乳腺癌-卵巢癌綜合征呈常染色體顯性遺傳，外顯率約為 39%~68%。BRCA1基因致病變異女性攜帶者，到70歲時患乳腺癌的累計風險達到 51%~95%，患卵巢癌的累計風險達到22%~60%。
BRCA1/2致病或可能致病的胚系突變患者的直系親屬屬于乳腺癌/卵巢癌/胰腺癌（女性）和前列腺/胰腺癌（男性）的高風險人群，建議其進行基因檢測篩查。
全球每年有120萬女性患乳腺癌，50萬女性死于乳腺癌。自20世紀70年代末以來，乳腺癌的發病在全球范圍內一直位居女性腫瘤的首位，并且以每年2%的速度遞增。
乳腺癌是主要危害婦女身體健康的疾病，男性也可患乳腺癌，但發病率遠低于女性。資料表明，近年來我國女性乳腺、卵巢癌的發病正向著年輕化、惡性高的方向發展。據2013年的有關資料表明，乳腺癌的發病率在女性為52/100000，占全身各種惡性腫瘤的7~10%。其發生年齡大多在40~60歲，或絕經期前后的婦女，尤其以45~49歲和60~64歲間發病率最高。
乳腺癌易感基因包括BRCA1和BRCA2。BRCA基因突變會導致基因組不穩定性顯著增加，從而顯著提高女性罹患乳腺癌、卵巢癌以及其他癌癥（如：胰腺癌和前列腺癌等）的風險。
BRCA1/2基因檢測為乳腺癌/卵巢癌患者明確致病原因及制定合理的個性化診療方案提供參考依據，也可評估健康人群（特別是有乳腺癌/卵巢癌家族史的人群）患卵巢癌、乳腺癌、胰腺癌、前列腺癌等相關腫瘤的風險，為疾病早防早治提供參考依據。
1. 診斷年齡≤40歲的早發性乳腺癌/卵巢癌患者；
2. 有乳腺癌和/或卵巢癌家族史；
3. 雙側乳腺患癌，或者在一側乳腺或卵巢有多于一個的腫瘤發生部位；
4. 同時患有乳腺癌和卵巢癌；
5. 男性乳腺癌，或有男性近親患有乳腺癌；
6. 家系中有已知BRCA1/2致病基因存在；
7. 有其他類型腫瘤的患者或家族史：胰腺癌、前列腺癌。
參考文獻：
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