Sunday, October 2, 2011
Not sure how many facts I'll get to, but here's the first one :)
Fact About Down Syndrome #1: There are 3 types of Down syndrome - Nondisjunction which makes up about 94% of all cases, it means every cell has an extra 21st chromosome. (This is what Jack and Dasha both have.).
Translocation makes up 3-4% of all cases. This can be (but is not always) an inherited form of Down syndrome.
Mosaic makes up 2% of all cases. This means that not every cell has the extra chromosome, only some of them do.
The diagnosis of Down syndrome is made by a chromosome analysis test called a Karyotype.