Down syndrome itself is a genetic condition caused when an unusual cell division results in an extra full or partial copy of chromosome 21, according to the Mayo Clinic.

Down syndrome, which causes a range of developmental differences and affects 1 in 700 newborns in the United States, is caused by the presence of an extra copy of chromosome 21. Mongkolchon ...

Down syndrome communities have built strong followings on social media, using well-known hashtags like #DownSyndrome and #DownSyndromeAwareness to connect and share their stories.

PHILADELPHIA (WPVI) -- Friday is World Down Syndrome Day. It is observed on March 21 to signify the uniqueness of the triplication of the 21 chromosome, which causes Down Syndrome.