Down syndrome is the most frequent genetic cause of intellectual disability, associated with multiple comorbidities, due to the presence of all or part of a third copy of chromosome 21. Although improvements in health care have remarkably increased life expectancy of people living with Down syndrome, a consequence has been the emergence of age-related diseases including Alzheimer’s disease (AD). People with Down syndrome have a high risk of developing AD dementia.
In a new study published in the journal JAMA Network Open, researchers assessed whether variability in AD symptom onset in people with Down syndrome is similar to autosomal AD and assessed its association with mortality. The study combined meta-analysis with the assessment of mortality data from US death certificates (77,347 record) obtained in the past 50 years and from a longitudinal cohort study from the Down Alzheimer Barcelona Neuroimaging Initiative (DABNI), which included 889 individuals. Researchers investigated the age at onset, age at death and duration of AD dementia in Down syndrome. The estimated age of onset was found to be 53.8 years, the estimated age at death 58.4 years and the estimated disease duration 4.6 years. In addition, US mortality data revealed an increase in life expectancy in Down syndrome from a median of 1 year in 1968 to 57 years in 2019.
These findings suggest that the variability in symptom onset of AD in people with Down syndrome was comparable to those who experienced autosomal dominant AD, while mortality was also similar.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2792538