BackgroundThe aim of this study was to test the usefulness of the Cognitive and Language scales Bayley‐III in the early assessment of cognitive and language functions in the context of an autism spectrum disorder (ASD) diagnosis. This paper focuses on the application of the Bayley‐III and studies the predictive value of the test result in children with ASD with different levels of verbal ability.MethodA sample of 135 children (121 boys, 14 girls) with a confirmed ASD diagnosis at age 4 years were assessed with the Bayley‐III before 42 months of age (m = 36.49, s = 4.46) and later with other rating scales of different psychological and psycholinguistic functions as part of a longitudinal study [McCarthy Scales of Children's Abilities (MSCA) (n = 48, 90% boys), Kaufman Assessment Battery for Children (K‐ABC) (n = 38, 87% boys) or Illinois Test of Psycholinguistic Abilities (ITPA) (n = 44, 89% boys)]. Age assessment in months: MSCA (m = 48.80, s = 3.33), K‐ABC (m = 51.80, s = 7.17) and ITPA (m = 54.48, s = 3.34).ResultsLower scores on the cognitive and language Bayley‐III scales before 3.5 years of age predicted lower cognitive and oral language levels at 4 years of age. A significant correlation was found between the Cognitive Bayley‐III Scale and the General Cognitive MSCA Scale, and with the Compound K‐ABC Mental Processing. An association between the nonverbal cognitive level and oral language level acquired at 4 years of age was found.ConclusionsThe Bayley‐III is a useful instrument in cognitive and language assessment of ASD.

Fragile X syndrome (FXS) causes intellectual disability and is the known leading cause of autism. Common problems in FXS include behavior and social problems. Along with syndromic characteristics and autism comorbidity, environmental factors might influence these difficulties. This systematic review focuses on the last 20 years of studies concerning behavior and social problems in FXS, considering environmental and personal variables that might influence both problems. Three databases were reviewed, leading to fifty-one studies meeting the inclusion criteria. Attention deficit hyperactivity disorder (ADHD) problems remain the greatest behavior problems, with behavioral problems and social competence being stable during the 20 years. Some developmental trajectories might have changed due to higher methodological control, such as aggressive behavior and attention problems. The socialization trajectory from childhood to adolescence remains unclear. Comorbidity with autism in individuals with FXS increased behavior problems and worsened social competence profiles. At the same time, comparisons between individuals with comorbid FXS and autism and individuals with autism might help define the comorbid phenotype. Environmental factors and parental characteristics influenced behavior problems and social competence. Higher methodological control is needed in studies including autism symptomatology and parental characteristics. More studies comparing autism in FXS with idiopathic autism are needed to discern differences between conditions.

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