Facts about Down Syndrome

Down syndrome is a common condition and the single most common cause of a learning disability. It occurs at the rate of about 1 in 600 – 1000 births. The life expectancy of a person with Down syndrome is now 60 to 65 years with some living even beyond this age. Down syndrome has existed since 
the beginning of mankind, but has been described in the scientific literature as a specific condition only since 1866. Children with Down syndrome are born to parents of all social and educational levels, in all ethnic groups, to parents of all ages. The chance of having a baby with Down syndrome increases with maternal age, even more after 35 years, however most babies with Down syndrome are born to mothers under 35.

Chromosomes and genes

Down syndrome is a chromosomal disorder. A person with Down syndrome has an extra copy of chromosome 21 
(all or part of the extra chromosome). 
This means the person will have 47 chromosomes instead of 46. The reason why this happens is still unknown. Chromosome 21 is the smallest of the human chromosomes. Down syndrome cannot be prevented from occuring, nor can it be cured. But with the current knowledge of genetics we know much more about the functioning of the chromosoms, especially about the number 21. This helps us to understand the typical features of the syndrome and may enable us to provide better medical care and intervention methods in the future.

What is the effect of the extra chromosome?

Medical status and cognitive development are affected. Some individuals with Down syndrome may have serious health problems, others have few or no additional health problems. They usually experience some degree of cognitive disability.

The development of children with Down syndrome varies widely and, like everyone, they continue to learn into adult life, if given the opportunity to do so. However it is important to note that, like everyone else, each child or adult must be considered as an individual and it is not possible to predict the future development of a baby with Down syndrome.