Kinney D K, Matthysse S
Annu Rev Med. 1978;29:459-73. doi: 10.1146/annurev.me.29.020178.002331.
There is convincing evidence form consanguinity, twin, and especially adoption studies that schizophrenia has a genetic component. There is also evidence from studies of MZ twins for an environmental component. It is not known whether the relevant environmental factors are prenatal or postnatal, psychosocial or physical; the presence of schizophrenia in the rearing family does not seem to be etiologically significant. It is likely that schizophrenia, especially if defined by symptoms alone, is etiologically heterogeneous. Study of pedigrees with several affected individuals is a useful approach to resolving this heterogeneity. The relevant genes may not code directly for schizophrenia, but for risk factors that predispose to the illness under particular environmental conditions. Careful methodology is needed to distinguish cause from effect of studying psychosocial factors. Genetic counseling is possible on the basis of empirical risk figures, but clarification of biological risk factors and environmental preciptants will make possible a much more rational approach to counseling and prevention.
来自近亲结婚、双胞胎尤其是收养研究的令人信服的证据表明，精神分裂症具有遗传成分。对同卵双胞胎的研究也有证据表明存在环境成分。目前尚不清楚相关环境因素是产前还是产后的，是心理社会因素还是身体因素；养育家庭中精神分裂症的存在似乎在病因学上并不重要。精神分裂症很可能在病因上是异质性的，尤其是仅由症状定义时。对有多个患病个体的家系进行研究是解决这种异质性的一种有用方法。相关基因可能并不直接编码精神分裂症，而是编码在特定环境条件下易患该疾病的风险因素。需要谨慎的方法来区分研究心理社会因素时的因果关系。基于经验风险数据可以进行遗传咨询，但明确生物风险因素和环境诱因将使咨询和预防方法更加合理。
