Down Syndrome is a genetic condition caused by extra genetic
material ( genes ) from the 21st chromosome . The extra genes
cause certain characteristics that we know as Down syndrome .
Individuals with Down syndrome also have all the other genes
given to them by their parents .
As a result they have a combination of features typical of Down
syndrome on top of the individual features from their parents .
This includes some degree of mental retardation or cognitive
disability and other developmental delays . some of the physical
traits that are common , but not always present are epicanthal
folds over the eyes , flattened bridge of the nose , a single palmar
crease and decreased muscle tone .
Down syndrome gets its name from the British doctor , John
Langdon Down, who first clinically identified the condition in 1866
The actual chromosomal nature of Down syndrome did not become
documented until 1959 by Dr. Le jeune . However , Down ‘s name
remains associated with condition >
Also though the term has nothing whatever to do with the physical
direction ” Down ” .
Ann Fortis who has Down syndrome has coined the term
” Up Syndrome ” to provide a different perspective on the
We don”t know what causes the extra 21st chromosome . We
know that the extra 21st chromosome an extra dose of some
proteins , which cause the typical features of Down syndrome
We do”t know most of the proteins involved and how they cause
Down syndrome We do know there is an association between a
mother`s age and the chances of having a baby with Down
syndrome . No causes have been identified and proven however .