Changes

'''Down syndrome''' (also written as '''Down's syndrome''', technical name '''Trisomy 21'''<ref>http://www.ds-health.com/trisomy.htm</ref>) is a genetic disorder caused by an extra copy of [[chromosome]] 21. IT is the most common syndrome caused by chromosomal abnormalities in human beings. The greatest risk factor for having a child with Down syndrome is increased maternal (and, to a lesser extent, paternal) age.  

'''Down syndrome''' (also written as '''Down's syndrome''', technical name '''Trisomy 21'''<ref>http://www.ds-health.com/trisomy.htm</ref>) is a genetic disorder caused by an extra copy of [[chromosome]] 21. It is the most common syndrome caused by chromosomal abnormalities in human beings. The greatest risk factor for having a child with Down syndrome is increased maternal (and, to a lesser extent, paternal) age.  

== History ==

== History ==