Down syndrome: the prevalence of Alzheimer’s disease and the role of thyroid hormone

Abstract

Trisomy of chromosome 21 causes Down syndrome (DS) and affects around 1 in 700 live births in the USA and 11.2 in 10,000 live births in Europe. For about a century, the birth of individuals with DS was associated with advanced maternal age and now the cases of late motherhood are becoming more common. DS is the most common genetic disorder that causes intellectual disability; and advancements in science in developed countries have made it possible for people affected by this syndrome to live longer, but an extended life span has brought with it Alzheimer's disease (AD), which exacerbates the cognitive decline in these individuals. The onset of AD occurs much earlier in DS individuals than in the general population. AD is a severe progressive neurodegenerative disease, which induces decreasing memory capacity and cognition. Several important genes related to AD are