Down syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all, or part of a third copy of chromosome 21. It is typically associated with physical growth delays, characteristic facial features, and mild to moderate intellectual disability.
Chromosomes are the cellular structures that contain the genetic information.
Amniocentesis is a prenatal test in which a small amount of amniotic fluid is removed for analysis. This test is performed between 15 and 20 weeks of pregnancy and can indicate chromosomal abnormalities such as Down syndrome, or genetic disorders such as Tay Sachs disease, sickle cell disease, cystic fibrosis, and others. It can also detect the baby’s sex and risk of spina bifida (a condition in which the brain or spine do no not develop properly).