# Human Cyclops
**URL:** https://boards.straightdope.com/t/human-cyclops/229880
**Category:** Factual Questions
**Created:** [February 18, 2004, 10:12pm UTC](https://boards.straightdope.com/t/human-cyclops/229880 "2004-02-18T22:12:50Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@David\_Plankton](https://boards.straightdope.com/u/David_Plankton)
#### Post date: [February 18, 2004, 10:12pm UTC](https://boards.straightdope.com/t/human-cyclops/229880/1 "2004-02-18T22:12:50Z")
Does anyone know if there has ever been a documented case of a human cyclops?
I seem to remember stories of farm animals being born as such.
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### Author:  [@hajario](https://boards.straightdope.com/u/hajario)
#### Post date: [February 18, 2004, 10:21pm UTC](https://boards.straightdope.com/t/human-cyclops/229880/2 "2004-02-18T22:21:06Z")
It’s called [cyclopia](http://depts.washington.edu/ceeh/News/sonic.htm) and it’s very rare.
> [@](#):
>
> About one in 16,000 babies is born with some form of cyclopia, technically known as holoprosencephaly (HPE). Early in pregnancy, before nature exerts quality control and flawed embryos are spontaneously aborted, the rate is much higher: one in 250. People with the mildest form of the disorder may have signs as minor as a single front incisor; severe cases are marked by one eye in the middle of the face, below a protruding nasal structure, and serious brain abnormalities. Infants with full-blown cyclopia die soon after birth.
Haj
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### Author:  [@kellner](https://boards.straightdope.com/u/kellner)
#### Post date: [February 18, 2004, 10:27pm UTC](https://boards.straightdope.com/t/human-cyclops/229880/3 "2004-02-18T22:27:06Z")
Definitely yes.
[This](http://web.vet.cornell.edu/CVM/HANDOUTS/plants/birth-defects647/sld018.htm) is the only picture I found so far. In addition to that I remember seeing several examples on a TV program on an anatomical collection (in Vienna I think).
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### Author:  [@jk1245](https://boards.straightdope.com/u/jk1245)
#### Post date: [February 18, 2004, 10:29pm UTC](https://boards.straightdope.com/t/human-cyclops/229880/4 "2004-02-18T22:29:38Z")
Yes. The condition is called cyclopia. A Google search will tell you all you want to know (and show you more than you probably want to see).
I can’t seem to find rates of occurance, but suffice to say it is rare, but not unheard of.
Actually, I did find rates of occurance. About 1 in 16,000. Though few have the most severe form (one eye), and those that do don’t live long if they are even alive at birth. Strangley, most are female also.
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### Author:  [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)
#### Post date: [February 19, 2004, 12:23am UTC](https://boards.straightdope.com/t/human-cyclops/229880/5 "2004-02-19T00:23:13Z")
According to a Google image search, many cases of Cyclopia—not always in humans—have two eyeballs “fused” into a single eye, in a single socket, but that have two pupils, irises, etc.
I think this one gives Harlequin Ichthyosis a run for it’s money.
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### Author:  [@Phage](https://boards.straightdope.com/u/Phage)
#### Post date: [February 19, 2004, 12:39am UTC](https://boards.straightdope.com/t/human-cyclops/229880/6 "2004-02-19T00:39:01Z")
What is this about a sonic hedgehog being involved in Cyclopia? Did someone really name a protein that, or should we be blaming Sega?
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### Author:  [@Broomstick](https://boards.straightdope.com/u/Broomstick)
#### Post date: [February 19, 2004, 2:09am UTC](https://boards.straightdope.com/t/human-cyclops/229880/7 "2004-02-19T02:09:49Z")
It’s not a protein, it’s a gene, and yes, they really did name it “sonic hedgehog”
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### Author:  [@jk1245](https://boards.straightdope.com/u/jk1245)
#### Post date: [February 19, 2004, 4:42am UTC](https://boards.straightdope.com/t/human-cyclops/229880/8 "2004-02-19T04:42:39Z")
Sonic hedgehog is the mammalian homologue of the Drosophila gene known as hedgehog (there are 2 other mammalian genes- Indian hedgehog and desert hedgehog). It encodes a protein that is vital to early embryonic development. In addition to birth defects, SHH is overactive in a wide range of digestive tract tumors.
Its function appears to be induction of early limb development, neural tube development, and other important embryonic milestones.
Interestingly, SHH is affected by cholesterol signaling, as alluded to in **hajario’s** link.