Trisomy 18p

What is Trisomy 18p?

Trisomy 18p is an extremely rare chromosomal anomaly with a poorly defined clinical phenotype. Reported manifestations include short stature, mild, moderate or severe developmental delay and intellectual disability, variable but mild facial dysmorphism, and epilepsy.

Other condition names

  • Duplication 18p
  • Duplication of the short arm of chromosome 18
  • Trisomy of the short arm of chromosome 18


  • Worldwide: <1 in 1,000 000

Age of Onset

  • Adolescent
  • Adult
  • Childhood
  • Infancy
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