What is trisomy 18?

Also known as: Edwards syndrome, chromosome 18 duplication

Trisomy 18 is a chromosome disorder that is present at birth. Patients with the condition have a third copy of chromosome 18 in their cells, which leads to a variety of lifelong symptoms ranging from intellectual disability to heart defects, a small and abnormally shaped head, low birth weight, clenched and overlapping fingers and more. Some people only have some cells with an extra chromosome 18, which is known as mosaic trisomy 18.

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Reviewed by: Gwen E Erkonen, MD

This page was last updated on: 1/29/2019 3:21:13 PM