Department of Child & Adolescent Psychiatry, Institute of Psychiatry, King's College London, United Kingdom.
Autism Res. 2011 Oct;4(5):377-82. doi: 10.1002/aur.207. Epub 2011 Jul 15.
It has been questioned whether the process of twinning might be a risk factor for autism spectrum conditions (ASC) and autistic traits.
We sought to determine whether autistic traits and probable disorder, as measured by the Childhood Autism Spectrum Test (CAST), were more pronounced in twins compared to singletons.
Data were analyzed from two large population-based samples of UK children, twins (n = 5,142 twin pairs, aged 8 years) and singletons (n = 2,805, aged 5-9 years).
Distributions of CAST scores in both groups were negatively skewed and scores for twins were more variable than singletons. Mean CAST total scores and standard errors (SE) were not significantly different for twins (5.1; SE 0.04) compared to singletons (4.9; SE 0.08). Moreover, contrary to expectations, the likelihood of scoring above the threshold for possible ASC was significantly lower in the twins than the singletons (OR = 0.69; P = 0.002). Subsidiary analyses of CAST scores according to sex, twin type, and subscale scores representing the subdomains of autism found a few significant differences (P<0.01), but the effect sizes for these differences were small and none exceeded η(2) = 0.005. The explanation for these small differences remains obscure, but the very small effect sizes mean they are of little importance.
Our results do not provide evidence to support twinning as a risk factor in the development of autistic traits.
人们质疑双胞胎的形成过程是否是自闭症谱系障碍（ASC）和自闭症特征的一个风险因素。
我们旨在确定自闭症特征和可能的障碍（通过儿童自闭症谱系测试（CAST）来衡量）在双胞胎中是否比在 singleton 中更为明显。
数据来自英国儿童的两个大型基于人群的样本，双胞胎（n=5142 对双胞胎，年龄 8 岁）和 singleton（n=2805，年龄 5-9 岁）。
两组的 CAST 分数分布均呈负偏态分布，且双胞胎的分数变化更为多样。双胞胎的 CAST 总分和标准误差（SE）平均值（5.1；SE 0.04）与 singleton（4.9；SE 0.08）无显著差异。此外，与预期相反，双胞胎得分高于可能的 ASC 阈值的可能性明显低于 singleton（OR=0.69；P=0.002）。根据性别、双胞胎类型和代表自闭症子领域的子量表分数对 CAST 分数进行的亚组分析发现了一些显著差异（P<0.01），但这些差异的效应大小较小，没有一个超过 η(2)=0.005。这些小差异的解释仍不清楚，但这些非常小的效应大小意味着它们意义不大。
我们的结果没有提供证据支持双胞胎作为自闭症特征发展的风险因素。
