Trisomy 18, also called Edwards syndrome, is the second-most common constitutive chromosomal abnormality after Down syndrome.

Key Data

< swipe to see entire table >
Synonym Edwards syndrome
Gene Trisomy 18
Gene product Not applicable
Function Not applicable
Heredity Sporadic
Prevalence 1:6.000-1:8.000 live births
Genotype-phenotype correlation Children with mosaicism or partial trisomy 18 have a better prognosis.
Penetrance Complete as far as is known
< swipe to see entire table >



The diagnosis is made clinically and confirmed by chromosomal analysis.

Differential Diagnoses

  • Other malformation syndromes

Clinical Presentation

Clinical Presentation

Trisomy 18 is characterized by various malformations, growth retardation, developmental delay, and an intellectual disorder. In the first 5 years of life, 90% of those affected die because of heart or kidney abnormalities, eating disorders, infections, or apnea. Hepatoblastomas and Wilms tumors are the most common tumors. The risk of the latter is around 1%.

Therapeutic Considerations

Treatment by a multidisciplinary team is necessary.

Surveillance Recommendations

Surveillance Recommendations

  • Early detection of a Wilms tumor with ultrasound, every 3 months until the age of 7

  • Early detection of hepatoblastoma with AFP and an abdominal ultrasound, every 3 months until age 4

  • Due to the poor prognosis, this is a matter of controversy and is by no means clearly indicated.

Additional Information

Open Clinical Trials / Registries

There are currently no open clinical trials/registries for patients with trisomy 18 that we can recommend to you for more information.

Support Groups