Jiajun Zhong
Dr. Elisabeth
Canvas
Spr19_PHSC002_30490
16/5/2019
DNA Fact Sheet
Down Syndrome
Down syndrome (DS) becomes a chromosomal genetic defect that results when there is an error
during cell division in extra chromosome 21 (Kazemi et al., 2016). It causes intellectual
disabilities that occur in every 1 in 400 newborns.
Facts
-It occurs when some or all of an individual’s cells have an extra full or partial copy of
chromosome 21 (the protein) (Crosta, 2017). Normally, there are two copies of every
chromosome, however, in DS they are three. The overexpression of a gene(s) found on the
triplicated chromosome causes DS.
