Down syndrome (DS or DNS), also known as trisomy 21, is a genetic disorder
caused by the presence of all, or part of a third copy of chromosome 21.
About 95 percent of the time, Down syndrome is caused by trisomy 21 — the
child has three copies of chromosome 21 (instead of the usual two copies) in all ...
Jan 17, 2014 ... Down syndrome is caused by a random error in cell division that results in the
presence of an extra copy of chromosome 21. The type of error is ...
Down syndrome is a set of physical and mental traits caused by a gene problem
that happens before birth. Children who have Down syndrome tend to have ...
Oct 28, 2015 ... Down syndrome is the most common genetic condition in the United States. It
causes physical and mental developmental delays and ...
A century after Down syndrome was first described, scientists discovered that the
root cause of this disorder is a condition called trisomy 21. What strides in ...
Down syndrome aka trisomy 21 is the most common birth defect in the United
States. Learn more about the causes, symptoms and risks of Down Syndrome.
Mar 3, 2016 ... Down syndrome is also referred to as Trisomy 21. This extra copy changes how
the baby's body and brain develop, which can cause both ...
In the first part of the twentieth century, there was much speculation of the cause
of Down syndrome. The first people to speculate that it might be due to ...
Down syndrome is a condition in which extra genetic material causes delays in
the way a child develops, both physically and mentally.