Giardiello F M, Brensinger J D, Petersen G M, Luce M C, Hylind L M, Bacon J A, Booker S V, Parker R D, Hamilton S R
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
N Engl J Med. 1997 Mar 20;336(12):823-7. doi: 10.1056/NEJM199703203361202.
The use of commercially available tests for genes linked to familial cancer has aroused concern about the impact of these tests on patients. Familial adenomatous polyposis is an autosomal dominant disease caused by a germ-line mutation of the adenomatous polyposis coli (APC) gene that causes colorectal cancer if prophylactic colectomy is not performed. We evaluated the clinical use of commercial APC gene testing.
We assessed indications for APC gene testing, whether informed consent was obtained and genetic counseling was offered before testing, and the interpretation of the results through telephone interviews with physicians and genetic counselors in a nationwide sample of 177 patients from 125 families who underwent testing during 1995.
Of the 177 patients tested, 83.0 percent had clinical features of familial adenomatous polyposis or were at risk for the disease-both valid indications for being tested. The appropriate strategy for presymptomatic testing was used in 79.4 percent (50 of 63 patients). Only 18.6 percent (33 of 177) received genetic counseling before the test, and only 16.9 percent (28 of 166) provided written informed consent. In 31.6 percent of the cases the physicians misinterpreted the test results. Among the patients with unconventional indications for testing, the rate of positive results was only 2.3 percent (1 of 44).
Patients who underwent genetic tests for familial adenomatous polyposis often received inadequate counseling and would have been given incorrectly interpreted results. Physicians should be prepared to offer genetic counseling if they order genetic tests.
使用与家族性癌症相关基因的商业检测引发了对这些检测对患者影响的关注。家族性腺瘤性息肉病是一种常染色体显性疾病，由腺瘤性息肉病 coli（APC）基因的种系突变引起，如果不进行预防性结肠切除术，会导致结直肠癌。我们评估了商业 APC 基因检测的临床应用情况。
我们通过电话访谈医生和遗传咨询师，评估了 APC 基因检测的指征、检测前是否获得知情同意并提供了遗传咨询，以及对 1995 年期间来自 125 个家庭的 177 名接受检测患者的全国性样本中检测结果的解读。
在 177 名接受检测的患者中，83.0%具有家族性腺瘤性息肉病的临床特征或有患该病的风险——这两者都是进行检测的有效指征。79.4%（63 名患者中的 50 名）采用了适当的症状前检测策略。检测前仅 18.6%（177 名中的 33 名）接受了遗传咨询，仅 16.9%（166 名中的 28 名）提供了书面知情同意。在 31.6%的病例中，医生对检测结果解读错误。在检测指征不常规的患者中，阳性结果率仅为 2.3%（44 名中的 1 名）。
接受家族性腺瘤性息肉病基因检测的患者往往接受的咨询不足，并且会得到错误解读的结果。如果医生开具基因检测医嘱，应准备好提供遗传咨询。
