Riccardi V M, Lewis R A
Department of Medicine, Baylor College of Medicine, Houston, TX 77030.
Am J Hum Genet. 1988 Feb;42(2):284-9.
This paper reviews the concepts of penetrance and expressivity and examines their application to the specific disorder von Recklinghausen neurofibromatosis. The data suggest that assessments of penetrance among predecessors to probands yield results different from those of assessments of penetrance among descendants to probands. For descendants at risk, penetrance is very close to 100%. For predecessors at risk, extremely variable expressivity may confound estimates of penetrance; as a specific example, a family is described in which two brothers have bona fide von Recklinghausen neurofibromatosis and their mother manifests the neurofibromatosis mutation only as iris Lisch nodules.
本文回顾了外显率和表现度的概念,并探讨了它们在特定疾病——冯雷克林霍增氏神经纤维瘤病中的应用。数据表明,对先证者的前辈进行外显率评估所得到的结果,与对先证者的后代进行外显率评估的结果不同。对于有患病风险的后代,外显率非常接近100%。对于有患病风险的前辈,表现度的极大变异性可能会混淆外显率的估计;作为一个具体例子,本文描述了一个家族,其中两兄弟患有确诊的冯雷克林霍增氏神经纤维瘤病,而他们的母亲仅表现为虹膜错构瘤,即携带神经纤维瘤病突变。