October 15, 2014
by Joaquin Espinosa
HHMI Early Career Scientist
What images and thoughts come to your mind when you think of Down syndrome?
Do you think of cognitive disabilities, short stature and contagious smiles? There is something that you are probably not thinking about: Our friends and relatives with Down syndrome may hold a cure for cancer.
Down syndrome is caused by an extra copy of chromosome 21. Instead of inheriting just two copies of every chromosome, one from each parent, individuals with Down syndrome carry a third copy of chromosome 21. This chromosome is very small compared with other chromosomes, and it carries only a few hundred of the 20,000-plus genes in every human cell. However, an extra copy of this tiny piece of DNA suffices to cause all the features of Down syndrome, including but not restricted to intellectual disabilities, short stature, congenital heart defects and increased risk of developing Alzheimer's disease.