The identification of protein biomarkers for oxidative stress in Down syndrome.

Down syndrome (DS) is a chromosomal abnormality due to partial or complete triplication of chromosome 21 (HSA21), and is the most common genetic cause of intellectual disability. DS may be considered a multifactorial disease, where an abnormal expression of trisomic genes arises not only from genetic, but also environ mental factors [1]. Thus, trisomy leads to a deregulated scenario that also affects disomic genes and that ultimately results in largely different phenotypes [2]. In fact, DS patients present a high variability of symptoms, including premature aging, mental retardation and Alzheimer’s-like dementia. Thus, above 40 years of age these persons develop a form of dementia with several clinical and neuropathologic characteristics of Alzheimer’s disease (AD), although with an earlier age of onset [3].