Edwards syndrome

Chromosomal imbalance syndrome, pair 18, trisomy; Complete trisomy 18 syndrome; E3 Trisomy; Trisomy 16-18; Trisomy 18 syndrome; Trisomy E syndrome

Trisomy 18 or Edwards Syndrome (named after John H. Edwards who first described the syndrome in 1960) is a genetic disorder. It is the second most common trisomy after Down Syndrome. It is caused by the presence of three — instead of two — chromosomes 18 in a fetus or baby's cells. The additional chromosome usually occurs before conception, when egg and sperm cells are made. A healthy egg or sperm cell contains 23 individual chromosomes - one to contribute to each of the 23 pairs of chr ...