Trisomy 18 syndrome
Other Resources UpToDate PubMed

Trisomy 18 syndrome

Other Resources UpToDate PubMed


Also called Edwards syndrome. Represents chromosomal variations due to an extra chromosome 18 (complete, mosaic, or partial) occurring in 1 in 5500 live births. Characterized by multiple severe intrauterine growth abnormalities, low birth weight, and a greatly increased risk of stillbirth and neonatal mortality. Other signs and symptoms include characteristic craniofacial features (micrognathia, microcephaly, prominent occiput), short sternum, overlapping fingers with clenched fists, hypoplastic fingernails, rocker-bottom feet, intellectual disability, malformed kidneys, heart defects, and other organ malformations. Risk factors include increased maternal age. Parental genetic counseling may be warranted.

Management of neonates is complex, requiring a high degree of vigilance and numerous interventions such as tube feeding, gastrostomy, and airway clearance. Most infants die in the first year of life with <10% living beyond the first decade. Common causes of neonatal and infant death are progressive pulmonary hypertension and cardiac or cardiopulmonary arrest.


Q91.3 – Trisomy 18, unspecified

254266000 – Partial trisomy 18 in Edward's syndrome
51500006 – Complete trisomy 18 syndrome
59033006 – Anomaly of chromosome pair 18


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Last Updated:04/30/2023
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Trisomy 18 syndrome
A medical illustration showing key findings of Trisomy 18 syndrome : Apnea, Failure to thrive, Microcephaly, Micrognathia, Developmental delay, Hypertonia
Copyright © 2024 VisualDx®. All rights reserved.