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G597(P) Prevalence of Autism Spectrum Disorder in down syndrome may be higher than previously reported
  1. VK Ho
  1. Community Child Health, Lewisham & Greenwich NHS Trust, London, UK


Aims Children with down syndrome (DS) often have qualitative impairments in their social communication and interaction skills. Many (<10%) will be diagnosed with autism spectrum disorder (ASD), but often at a later age than their peers, due to “diagnostic overshadowing”.

An audit in 2013 suggested that 15% of children with DS had ASD. This study aimed to review this finding and associated patient characteristics.

Methods A retrospective analysis of community records of children with DS, aged 0–18 years, was undertaken between September and November 2015. The prevalence of ASD in DS was established and patient demographics, comorbidity and type of diagnostic assessment recorded.

Results 93 children were included in the study (Figure 1). 15 (16.1%) had confirmed ASD (mean age at diagnosis was 7.5 years, range 4–13 years) and a further 16 (17.2%) had social communication difficulties but no formal diagnosis. 9 (60%) children with ASD underwent a formal multidisciplinary (MD) autism assessment with a paediatrician and speech and language therapist. The remaining 6 (40%), were diagnosed by a paediatrician in a “virtual” MD clinic, where additional information from other professionals was reviewed.

Comorbidity and demographics are summarised in Table 1 . All children with ASD had variable hearing impairment with 3 (20%) requiring hearing aids; 1 (6.7%) had epilepsy; 1 (6.7%) had anorectal malformation; and 10 (66.7%) had congenital heart disease. 6 (40%) were attending mainstream educational settings when diagnosed.

Abstract G597(P) Figure 1

Prevalence of Autism spectrum disorder in children with down syndrome and type of diagnostic assessment used

Conclusion The prevalence of ASD is higher than expected in this cohort of children with DS. Those diagnosed with ASD, benefited from a multidisciplinary diagnostic assessment – albeit “virtual” in some cases. Most children had associated medical comorbidity, which was not unexpected.

Correct and early diagnosis of ASD means that parents and professionals are better able to understand and support the child with DS, using autism specific strategies. The dual diagnosis should facilitate a child’s access to appropriate educational and health resources (including transition to adult services) and bespoke communication and behavioural interventions. Professionals should be mindful of “diagnostic overshadowing” and consider ASD earlier in childhood.

Abstract G597(P) Table 1

Demographic details and medical comorbidity in children with down syndrome and autism spectrum disorder

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