*Downs Syndrome is caused during cell division of a sperm and egg. Usually a person has 23 pairs of chromosomes, but a person with Downs Syndrome has extra genetic material on one chromosome. This affects development and characteristic features.
There are three genetic variations that cause Downs Syndrome:
1. Trisomy 21- when a person has an extra copy of chromosome 21 in some cells. (Most common)
2. Mosaic Downs Syndrome- when a person has some cells with an extra copy of chromosome 21. When cells divide, it creates a "mosaic" of normal and abnormal cells in the person's body. (Rare)
3. Translocation Down Syndrome- when a person has an extra copy of chromosome 21 and it becomes attached to another chromosome.
(Mayo Clinic, 2014)
Create your own unique website with customizable templates.