Science / Genetics / Trisomy: Possessing three copies of a particular chromosome instead of the normal two copies.
Science / Genetics / Down Syndrome: A type of mental deficiency due to trisomy (three copies) of autosome 21, a translocation of 21 or mosaicism. MORE
Science / Genetics / Advanced Maternal Age: Women over age 34 (age 35 at delivery) at increased risk for nondisjunction trisomy in fetus. MORE