by Jos Van der Poel Down’s syndrome is a genetic disorder (in
stead of two these persons have three chromosomes 21) that
besides a number of physical characteristics leads to
intellectual impairment. It occurs in one out of every 1.000
births. Life expectancy of people with Down’s syndrome has
increased substantially over the last century: about 50 % of
them will reach the age of 60. Because of the trisomie 21 people
with Down’s syndrome have an overexpression of the amyloid
precursor protein. Amyloid is the main ingredient of the
plaques, which are found in the brains of people with
Alzheimer’s disease. Symptoms and course Not all persons with
Down’s syndrome show evidence of cognitive deterioration or
other clinical evidence of dementia even after extended periods
of observation. Clinical symptoms at first are increasing
depression, indifference and a decline in social communication.
Later symptoms are: seizures in previously unaffected persons,
changes in personality, loss of memory and general functions,