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Where on Chromosome is Problem?

The SHH gene is located on the long arm of chromosome 7 at position 36.
More specifically, the SHH gene is located from base pair 155,802,863 to base pair 155,812,272 on chromosome 7.

What Is the Problem?

A protein called "sonic hedgehog homolog" (yes, it is really named after the famous video game hedgehog) or SHH is said to be the cause of diprosopus because the protein has a corresponding gene. The SHH is responsible for signaling proper separation of, specifically, the face and ventral brain during development. Without the proper function of SHH, the face and brain may not fully separate resulting in nonsyndromic holoprosencephaly, or, may actually overseperate and form two faces/skulls bound at the dorsal portion- known as diprosopus.

Whoever has this disease, suffers with "two faces".

What is the Prognosis?

Life expectancy is not long with this disease. Most women can find out that their child has diaprosopus earlier in their preganancy. Most women are suggested to have an abortion because most babies are not expected to make it through the pregnancy.


Cite Your Sources

http://ghr.nlm.nih.gov/gene/SHH