Ljungquist B, Berg S, Lanke J, McClearn G E, Pedersen N L
Institute of Gerontology, University College of Health Sciences, Jönköping, Sweden.
J Gerontol A Biol Sci Med Sci. 1998 Nov;53(6):M441-6. doi: 10.1093/gerona/53a.6.m441.
The relative importance of genetic influences on longevity was studied on data from the population-based Swedish Twin Registry.
A sample of 3,656 identical and 6,849 like-sexed fraternal twin pairs was studied regarding mortality rates and within-pair similarity for age at death. Genetic and environmental contributions to variation in longevity, expressed by integrated mortality rates, were estimated from a subsample of 1,734 twin pairs reared together and 130 twin pairs reared apart from the cohorts born 1886 to 1900.
The intraclass correlation coefficients suggested that the genetic effect was small, and, for males, perhaps absent. Among pairs in which both twins died relatively young and among pairs in which both twins lived until very old age, the variance in age at death seemed to have no genetic component. Model fitting procedures based on twins reared apart and twins reared together indicated that most of the variance in longevity was explained by environmental factors.
Over the total age range examined, a maximum of around one third of the variance in longevity is attributable to genetic factors, and almost all of the remaining variance is due to nonshared, individual specific environmental factors. The evidence that genetic factors play a minor role depending upon age at death merits further examination.
基于瑞典全国双胞胎登记处的数据，对基因影响长寿的相对重要性进行了研究。
对3656对同卵双胞胎和6849对同性异卵双胞胎进行了研究，内容包括死亡率以及死亡年龄的双胞胎内相似性。从1734对共同抚养的双胞胎和130对分开抚养的双胞胎（出生于1886年至1900年的队列）的子样本中，估算了由综合死亡率表示的基因和环境对长寿差异的贡献。
组内相关系数表明基因效应较小，对于男性而言，可能不存在基因效应。在双胞胎均相对年轻时死亡的双胞胎对以及双胞胎均活到很高年龄的双胞胎对中，死亡年龄的差异似乎没有基因成分。基于分开抚养的双胞胎和共同抚养的双胞胎的模型拟合程序表明，长寿的大部分差异是由环境因素造成的。
在整个研究的年龄范围内，长寿差异中最多约三分之一可归因于基因因素，几乎所有其余差异都归因于非共享的、个体特定的环境因素。基因因素在取决于死亡年龄方面作用较小的证据值得进一步研究。
