Topic Completed: 1 March 2013

Minor changes: 25 September 2019

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PubMed Search: Cyclopia [title] eye

Deepali Jain, M.D.
Page views in 2019: 240
Page views in 2020 to date: 80
Cite this page: Jain D. General: cyclopia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/eyecyclopia.html. Accessed June 7th, 2020.
Definition / general
  • Rare (1 per 100K births) congenital abnormality with one medial eye (either single eye or 2 fused eyeballs) and proboscis (tubular appendage) superior to the orbit
  • Incompatible with life
  • Most severe facial expression of holoprosencephaly
  • Due to impaired midline cleavage of embryonic forebrain causing doubling of intrinsic ocular structures; may be associated with malfunction of sonic hedgehog protein
  • Female predominance (58%)
  • Associated with trisomy 13, trisomy 18, triploidy; also other chromosomal abnormalities (Am J Med Genet C Semin Med Genet 2011;157C:344)
Case reports
Clinical images

Images hosted on other servers:
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Single orbit with 2 fused eyes

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Trisomy 13 - cyclopia with proboscis

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