trisomy 18

synonym: Edwards syndrome

https://doi.org/10.1351/goldbook.11324

Presence of part or all of an extra chromosome 18 from nondisjunction during meiosis.

Note: This leads to multiple congenital abnormalities and mental retardation, and is usually fatal in early childhood.

Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 815 (https://doi.org/10.1515/pac-2015-1202)