Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17165 Stockholm, Sweden.
Tilburg School of Humanities and Digital Sciences, Department of Communication and Cognition, Tilburg University, 5037 AB Tilburg, The Netherlands.
Proc Biol Sci. 2023 Oct 25;290(2009):20231888. doi: 10.1098/rspb.2023.1888.
Synaesthesia is a sensory phenomenon where external stimuli, such as sounds or letters, trigger additional sensations (e.g. colours). Synaesthesia aggregates in families but its heritability is unknown. The phenomenon is more common in people on the autism spectrum compared with the general population and associated with higher autistic traits. Using classical twin design, we assessed the heritability of individual differences in self-reported synaesthesia and the genetic and environmental contributions to their association with autistic traits within a population twin cohort ( = 4262, age = 18 years). We estimated individual differences in synaesthesia to be heritable and influenced by environmental factors not shared between twins. The association between individual differences in synaesthesia and autistic traits was estimated to be predominantly under genetic influence and seemed to be mainly driven by non-social autistic traits (repetitive behaviours, restricted interests and attention to detail). Our study suggests that the link between synaesthesia and autism might reside in shared genetic causes, related to non-social autistic traits such as alterations in perception. Future studies building on these findings may attempt to identify specific groups of genes that influence both autism, synaesthesia and perception.
联觉是一种感官现象，外部刺激，如声音或字母，会引发额外的感觉（例如颜色）。联觉在家庭中聚集，但它的遗传性尚不清楚。与一般人群相比，自闭症谱系人群中这种现象更为常见，并且与更高的自闭症特征有关。我们使用经典的双胞胎设计，评估了在人群双胞胎队列中（= 4262，年龄= 18 岁），自我报告的联觉个体差异的遗传性，以及遗传和环境因素对其与自闭症特征关联的贡献。我们估计，联觉的个体差异是可遗传的，并受到双胞胎之间不共享的环境因素的影响。联觉个体差异与自闭症特征之间的关联估计主要受遗传影响，似乎主要由非社交自闭症特征（重复行为、兴趣受限和对细节的关注）驱动。我们的研究表明，联觉和自闭症之间的联系可能存在于共同的遗传原因中，这些原因与感知改变等非社交自闭症特征有关。基于这些发现的未来研究可能试图确定影响自闭症、联觉和感知的特定基因群。
