各种疾病与遗传因素和环境因素的关系图1所示。从遗传学的观点看,全部的疾病可分为:①特定的基因异常是发病的主要原因即“遗传病”(单基因疾病);②有多种遗传因素和环境因素参与的多因素疾病(复合疾病);③与基因完全无关的疾病。其中,①中的遗传病,特定的基因发生突变直接与发 The relationship between various diseases and genetic and environmental factors is shown in Figure 1. From a genetic point of view, all diseases can be divided into: ① specific genetic abnormalities is the main cause of the disease that is “genetic disease” (single gene disease); ② There are a variety of genetic and environmental factors involved in multi-factor disease Compound disease); ③ and the gene has nothing to do with the disease. Among them, ① genetic disease, mutation of specific genes directly with the hair