Objective

Atypical responses to sensory stimuli are common features of autism spectrum disorders (ASD). Consequently, atypical sensory reactivity (SR) is now a diagnostic feature of ASD. Quantitative genetic research on ASD has overlooked these symptoms, however. We therefore investigated the association between autistic traits and SR using twin methods.

Method

Autistic traits and SR were assessed by 2 separate scales in 12,419 Swedish twin pairs (n = 3,586 monozygotic [MZ], n = 8,833 dizygotic [DZ]) when the twins were 9 or 12 years of age. The classic twin design estimated the degree to which etiological factors associated with autistic traits were also associated with SR, and the degree to which such shared factors explained the covariance between these phenotypes. DeFries–Fulker analysis estimated the genetic correlation between screening diagnoses of ASD, defined broadly and strictly, and SR.

Results

Autistic traits and SR were both highly heritable (62%–75% and 66%–71%, respectively). There was a moderate phenotypic correlation between autistic traits and SR (r = 0.47). Genetic influences on these phenotypes correlated moderately (genetic correlation = 0.60). These overlapping genetic factors explained most of the correlation between autistic traits and SR. Genetic correlations with SR increased for broad ASD (genetic correlation = 0.72) and strict ASD (genetic correlation = 0.80).

Conclusion

The genetic overlap observed between autistic traits and SR lends quantitative genetic support to the notion that ASD and SR are strongly linked. Such symptoms may thus comprise part of the ASD genotype, as well as phenotype. Associations persisted across all definitions of ASD, indicating a genetic link between the broader ASD phenotype and SR.

中文翻译：

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研究自闭症特征与非典型感觉反应性之间的关联：一项孪生研究

客观的

对感觉刺激的非典型反应是自闭症谱系障碍（ASD）的共同特征。因此，非典型的感觉反应（SR）现在是ASD的诊断功能。然而，关于ASD的定量遗传研究忽略了这些症状。因此，我们使用孪生方法研究了自闭症特征与SR之间的关联。

方法

当双胞胎分别为9岁或12岁时，通过2个独立的量表对12,419对瑞典双胞胎（n = 3,586个纯合子[MZ]，n = 8,833个纯合子[DZ]）进行了自评。经典的双胞胎设计估计了与自闭症特征相关的病因因素也与SR相关的程度，以及这些共有因素解释了这些表型之间的协方差的程度。DeFries-Fulker分析估计了广义和严格定义的ASD筛查诊断与SR之间的遗传相关性。

结果

自闭症特征和SR都是高度遗传的（分别为62％–75％和66％–71％）。自闭症特征与SR之间存在中等表型相关性（r  = 0.47）。对这些表型的遗传影响具有中等相关性（遗传相关性= 0.60）。这些重叠的遗传因素解释了自闭症特征与SR之间的大多数相关性。广泛ASD（遗传相关= 0.72）和严格ASD（遗传相关= 0.80）与SR的遗传相关性增加。

结论

在自闭症特征和SR之间观察到的遗传重叠为ASD和SR紧密联系的观念提供了定量的遗传支持。这样的症状因此可以包括ASD基因型以及表型的一部分。协会一直存在于ASD的所有定义中，表明更广泛的ASD表型和SR之间存在遗传联系。