User talk:Swissarmy
Hi this is a test!
down syndrome
[edit]when a person has down syndrome his or her 22nd or 24th chromesomes dont split properly.they also may have an extra copy of the 21st chromesomes.
Hi this is a test!
when a person has down syndrome his or her 22nd or 24th chromesomes dont split properly.they also may have an extra copy of the 21st chromesomes.