Prevalence of autism and attention‐deficit–hyperactivity disorder in Down syndrome: a population‐based study

Abstract

Children with Down syndrome and coexisting neurodevelopmental/neuropsychiatric disorders in addition to intellectual disability and medical disorders constitute a severely disabled group. Based on the results, we suggest that screening is implemented for both ASD and ADHD, at the age of 3 to 5 years and early school years respectively, to make adequate interventions possible.

Correlates of early cognition in infants with Down syndrome

“…As early as 12 months, infants with DS demonstrate detectable delays on standardised assessments of cognition, and they show fewer cognitive gains from 12 to 30 months when compared to MA-matched children with other developmental delays (Fidler et al 2008;Visootsak et al 2013). While difficulties with attention and memory are core aspects of the cognitive phenotype associated with DS throughout childhood and into adulthood (Lanfranchi et al 2009;Oxelgren et al 2017), the underlying neuropsychological factors that contribute to slower rates of early cognitive development remain poorly understood. A consideration of both distal (biomedical) and proximal (neuropsychological) factors that impact early cognition can facilitate progress in early cognitive intervention in DS.…”

“…; Oxelgren et al . ), the underlying neuropsychological factors that contribute to slower rates of early cognitive development remain poorly understood. A consideration of both distal (biomedical) and proximal (neuropsychological) factors that impact early cognition can facilitate progress in early cognitive intervention in DS.…”

The Genetic and Epigenetic Basis Involved in the Pathophysiology of ASD: Therapeutic Implications

“…There are also many anecdotal reports of autism with visible chromosomopathies [21,22], and Down syndrome have been found with high rates of ASD of up to 42% [23]; and well-known microdeletion syndromes like 22q11 deletion syndrome divided into distinct syndromes (e.g., DiGeorge syndrome, velocardiofacial syndrome, and cardiofacial syndrome) in which more than 40% meet the criteria for either ASD, ADHD, or both [24]; as well as Angelman syndrome, or Smith-Magenis syndrome, are well known autism. Although the latter mentioned can be produced by different genetic mechanisms, Angelman syndrome is caused by deletion of the 15q11.2-q13 critical region (60-75%), paternal uniparental disomy (2-5%), imprinting defect (2-5%), and mutation in the UBE3A gene (10%); and Smith-Magenis syndrome is caused either by a 17p11.2 deletion encompassing the retinoic acid-induced 1 (RAI1) gene (90%) or a mutation of the gene (10%) [25].…”

Autism spectrum disorder and attention‐deficit–hyperactivity disorder in Down syndrome

“…The article by Oxelgren et al expands upon the existing evidence base, using an array of standardized diagnostic tools (informant report and direct observation methods) alongside rigorous clinical assessment, to evaluate the prevalence of ASD and ADHD in Down syndrome. The results demonstrate very high rates of both ASD and ADHD in this population‐based sample, and a strong association between these characteristics and the presence of intellectual disability.…”

“…2 While very little is currently known about the prevalence of attention-deficit-hyperactivity disorder (ADHD) in Down syndrome, studies suggest that individuals with Down syndrome who meet criteria for ASD show significantly more conduct problems and hyperactivity than those with Down syndrome who do not meet these criteria. 3 The article by Oxelgren et al 4 expands upon the existing evidence base, using an array of standardized diagnostic tools (informant report and direct observation methods) alongside rigorous clinical assessment, to evaluate the prevalence of ASD and ADHD in Down syndrome. The results demonstrate very high rates of both ASD and ADHD in this population-based sample, and a strong association between these characteristics and the presence of intellectual disability.…”