What is trisomy 18?

Trisomy 18, also known as Edward's syndrome, is a disorder of human chromosomes, where an extra copy of chromosome 18 is found in the cells. Full trisomy, where the extra chromosome is found in all the cells in the body, is found in 90% of infants with Edwards. The remaining 10% have a partial trisomy, where only part of the extra chromosome is found, or mosaicism, where the additional chromosomal material is only found in some cells of the body.

Edwards Syndrome is the second most common trisomy after Downs Syndrome (extra chromosome 21). However, unlike Downs syndrome, the survival rate is much lower, with only 10% of infants surviving to their first birthday. Statistics indicate approx 1 in 3000, 4000 or 5000 live births, although most die during pregnancy and do not make it full term. It can be detected whilst in the womb. Approx 80% cases are girls.

There is a range of symptoms of Trisomy 18 and varying degrees of severity. For more information on Trisomy 18, please visit these links, many of which are dedicated to those affected by Edwards.