Estimating Heritability and Shared Environmental Effects for Refractive Error in Twin and Family Studies
Estimating Heritability and Shared Environmental Effects for Refractive Error in Twin and Family Studies
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DOI：
10.1167/iovs.08-2385
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发表时间：
2009-01-01
影响因子：
4.4
通讯作者：
Hammond, Christopher J.
中科院分区：
文献类型：
--
作者：
Lopes, Margarida C.;Andrew, Toby;Hammond, Christopher J.
目的.双胞胎研究表明，屈光不正的遗传率高达90%，但一些家庭研究表明，高达三分之一的人口方差可归因于共同的家庭环境的影响。这项大型双胞胎研究旨在探讨共同环境在屈光不正中的作用。使用自动验光仪测量了4602例受试者（1152对同卵双生子和1149对异卵双生子）的屈光不正，年龄在16至82岁之间，从TwinsUK成人双生子登记处招募。最大似然法被用来估计遗传，环境和年龄方差分量的方差。最佳拟合模型的遗传度的最大似然模型拟合估计值为77%（95%置信区间[CI]，68%-84%）。共享环境效应解释了7%（95%CI，0%-15%），个体环境效应解释了16%（95%CI，15%-18%）的等效球镜方差。将年龄效应纳入建模中，将共享环境效应降低到估计的2%的变异。对2301对双胞胎的分析证实，双胞胎研究设计的结果在一个非常低的估计共享的家庭环境的影响，屈光不正。有几个因素可以解释这些差异;我们认为最有可能的是双胞胎的年龄完全匹配，不包括跨代或队列效应。这意味着双胞胎研究设计更有能力检测近视方差分量模型中的遗传效应，而家庭研究更有能力检测共享环境效应。（Invest Ophthalmol维斯科学。2009; 50：126-131）DOI：10.1167/iovs.08-2385
PURPOSE. Twin studies have demonstrated a high heritability for refractive error of up to 90%, but some family studies have suggested up to one-third of population variance is attributable to the effects of shared family environment. This large twin study aimed to explore the role of shared environment in refractive error.METHODS. Refractive error was measured using autorefraction in 4602 subjects (1152 monozygotic and 1149 dizygotic twin pairs), aged between 16 and 82 years, recruited from the TwinsUK Adult Twin Registry. Maximum-likelihood methods were used to estimate the variance of genetic, environmental, and age variance components.RESULTS. Maximum likelihood model fitting estimate of the heritability from the best-fit model was 77% (95% confidence interval [CI], 68%-84%). Shared environmental effects explained 7% (95% CI, 0%-15%) and individual environmental effects explained 16% (95% CI, 15%-18%) of the spherical equivalent variance, respectively. Inclusion of age effects into the modeling reduced shared environmental effects to an estimated 2% of variation.CONCLUSIONS. Analysis of 2301 twin pairs confirms that the twin study design results in a very low estimate of shared family environmental effects in refractive error. Several factors may explain these differences; we believe the most likely is that twins are perfectly age matched and do not include cross-generation or cohort effects. This means twin study designs have more power to detect heritable effects in variance component models of myopia, whereas family studies have more power to detect shared environment effects. (Invest Ophthalmol Vis Sci. 2009; 50: 126-131) DOI: 10.1167/iovs.08-2385