Abstract
Background. Sensory processing atypicalities are part of the core symptoms of autism spectrum disorder (ASD) and could result from an excitation/inhibition imbalance. Yet, the convergence level of phenotypic sensory processing atypicalities with genetic alterations in GABA-ergic and glutamatergic pathways remains poorly understood. This study aimed to characterize the distribution of hypo/hyper-sensory profile among individuals with ASD and investigate the role of deleterious mutations in GABAergic and glutamatergic pathways related genes in sensory processing atypicalities. Method. From the Short Sensory Profile (SSP) questionnaire, we defined and explored a score – the differential Short Sensory Profile (dSSP) - as a normalized and centralized hypo/hypersensitivity ratio for 1136 participants (533 with ASD, 210 first-degree relatives, and 267 controls) from two independent study samples (PARIS and LEAP). We also performed an unsupervised item-based clustering analysis on SSP items scores to validate this new categorization in terms of hypo and hyper sensitivity. We then explored the link between the dSSP score and the burden of deleterious mutations in a subset of individuals for which whole-genome sequencing data were available. Results. We observed a mean dSSP score difference between ASD and controls, driven mostly by a high dSSP score variability among groups (PARIS: p<0.0001, η2 = 0.0001, LEAP: p<0.0001, Cohen’s d=3.67). First-degree relatives were with an intermediate distribution variability profile (p<0.0001). We also reported a positive developmental trajectory of the dSSP score (PARIS: p=0.0006, η2 = 0.02; LEAP: p=0.01, η2 = 0.01). Clusters were similarly characterized by hypo- and hyper-sensitivity items in both study samples (Cramer's V from 0.64 to 0.69, p<0.05). Our genetic analysis showed a trend only for an association with mutations of the GABAergic pathway.Limitations. The major limitation was the dSSP score difficulty to discriminate subjects with a similar quantum of hypo- and hyper- sensory symptoms to those with no such symptoms, resulting both in a similar ratio score of 0.Conclusion. The dSSP score could be a relevant clinical score of the hypo/hyper-sensory individual profile in subjects with ASD. Combined with additional sensory domain characteristics, genetics and endophenotypic substrates, the dSSP score will offer new avenues to explore the underlying neurobiological mechanisms of sensory processing atypicalities in ASD.
Psychometric Evaluation of the Short Sensory Profile in Youth with Autism Spectrum Disorder
