Early non-social behavioural indicators of autism spectrum disorder (ASD) in siblings at elevated likelihood for ASD: a systematic review

Daniela Canu,Sara Van Der Paelt,Ricardo Canal-Bedia,Manuel Posada,Herbert Roeyers,Marleen Vanvuchelen

doi:10.1007/s00787-020-01487-7

Abstract

We aimed at identifying early non-social behavioural indicators that predict later ASD. Likewise, we were interested in the moment in which non-social signs discriminate between children at elevated likelihood for ASD with a later diagnosis of ASD, and children at elevated likelihood for ASD with a typical developmental outcome. In addition, we intended to explore the developmental evolution of children’s symptomatology over time. A systematic literature search was conducted for longitudinal studies on early non-social behavioural indicators among siblings at elevated likelihood for ASD. The following databases were searched: PUBMED, Web of Science, PsycINFO, CINAHL and EMBASE. The study identification process was conducted by two reviewers independently. Compared to siblings at elevated likelihood for ASD with a typical developmental outcome, siblings at elevated likelihood for ASD with later ASD show impairments in attention disengagement, in gross and fine motor development and characteristic restricted and repetitive interests and behaviours, starting at 12 months of age. Moreover, early attention disengagement exerts a predictive role towards a later ASD diagnosis, given that from 12 months siblings at elevated likelihood for ASD who will receive an independent ASD diagnosis towards 24–36 months present marked difficulties in disengaging in comparison with siblings at elevated likelihood for ASD that will not satisfy the criteria for an ASD diagnosis. The findings call for a more comprehensive vision on early indicators of ASD. Further research is needed to extend results to other behavioural domains.

Highlights

Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by a pattern of persistent impairments in social interaction and social communication across several contexts, together with narrow, stereotyped, repetitive behaviour [1]
The aims of the present review were: to summarize the state of the art on early non-social behavioural indicators of ASD that are able to discriminate between elevated likelihood for ASD (EL) and typical likelihood for ASD (TL) samples, as well as within the EL sample; to identify at what age EL subgroups differ in various non-social domains and to explore whether early non-social behaviours are good predictors for a later ASD diagnosis, clarifying the nature of this association and describing the developmental evolution over time
Zwaigenbaum et al [33] found that parents of EL-ASD described their children at 12 months with a tendency to fixate more on particular objects in the environment at the expense of a more active visual exploration, compared to parents of EL-TD and TL

Summary

Introduction

Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by a pattern of persistent impairments in social interaction and social communication across several contexts, together with narrow, stereotyped, repetitive behaviour [1]. The rate increases up to 18.7% [4] amongst younger siblings of children with ASD, considered at elevated likelihood for ASD (EL), suggesting a strong genetic contribution [5]. An early diagnosis of ASD can have a positive impact on children’s developmental outcome [6]. Many of these children experience diagnostic delays [7]. The average diagnostic age ranges between 38 and 120 months [8]. This finding is surprising, given that the majority of parents express their concerns before their child’s second birthday [9]

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