Yet, due to the inter- and intraindividual variability in intellectual disability (ID) as well as the heterogeneity in clinical symptoms (Beresford-Webb et al., 2021; Videla et al., 2022), the clinical diagnosis of AD in DS (DS-AD) remains challenging and is often misdiagnosed as a psychiatric disorder, delaying appropriate treatment with acetylcholinesterase inhibitors or an n-methyl-d-aspartate inhibitor as well as a timely initiation of supportive and social measures with high relevance to their everyday lives. Here, ACHE is linked to Alzheimer disease.