McPherson Elizabeth
Medical Genetics Services, Marshfield Clinic, Marshfield, WI 54449, USA.
Clin Med Res. 2006 Jun;4(2):123-9. doi: 10.3121/cmr.4.2.123.
Genetic testing is defined as "the analysis of human DNA, RNA, chromosomes, proteins and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes or karyotypes for clinical purposes." This article focuses on diagnostic and predictive genetic testing. The latter includes presymptomatic testing, which identifies individuals who are expected to become ill in the future and predisposition testing, which identifies those who are at increased risk of becoming ill. Decisions regarding genetic testing must be based not only on the analytic accuracy, availability and cost of the test, but on the clinical utility as well, including the sensitivity, specificity and interpretability of results. Clinical information, including the medical and family history and the findings of the physical examination, is vital for the selection of appropriate diagnostic tests, as well as the interpretation of the results. Presymptomatic genetic testing is a very personal choice that should only be made after the patient has had sufficient counseling to develop an understanding of the risks and benefits of the test and is able to make an informed decision. The same principle applies to predisposition testing; however, additional factors, such as the probability of a positive result, the likelihood that the disease will actually develop in those with positive results, the effect on the management of the index patient, the effects on family members, the risk of false reassurance if the result is negative or the potential for loss of hope if it is positive, all contribute to the assessment of risk versus benefit. Clinical evaluation and counseling of the patient who is at risk for a genetic disorder are labor intensive but essential for the selection and interpretation of genetic tests.
基因检测被定义为“对人类DNA、RNA、染色体、蛋白质和某些代谢物进行分析，以便出于临床目的检测与遗传性疾病相关的基因型、突变、表型或核型”。本文重点关注诊断性和预测性基因检测。后者包括症状前检测，即识别预计未来会患病的个体，以及易感性检测，即识别患病风险增加的个体。关于基因检测的决策不仅必须基于检测的分析准确性、可获得性和成本，还必须基于临床实用性，包括结果的敏感性、特异性和可解释性。临床信息，包括病史、家族史和体格检查结果，对于选择合适的诊断检测以及解读结果至关重要。症状前基因检测是一个非常个人化的选择，只有在患者得到充分咨询，对检测的风险和益处有了理解并能够做出明智决定之后才能进行。同样的原则也适用于易感性检测；然而，其他因素，如阳性结果的概率、结果呈阳性者实际患该病的可能性、对索引患者管理的影响、对家庭成员的影响、结果为阴性时错误安慰的风险或结果为阳性时失去希望的可能性等，都有助于风险与益处的评估。对有遗传疾病风险的患者进行临床评估和咨询工作强度大，但对于基因检测的选择和解读至关重要。
