Rare diseases — Medical conditions you may never have heard of before
![An old medical illustration of the human body](https://cdn.mos.cms.futurecdn.net/MjMTJtGE9k9Wy5tXafnVLP-1200-80.jpg)
Cancer, heart disease, the common cold — these medical conditions are well-known by the public, in part, because they affect large numbers of people. But did you know there's a genetic condition that causes babies to suddenly lose all their fat after birth? Or an aggressive autoimmune disorder that can cause the bridge of the nose to collapse? Or a disease that causes the skin to blister under even the lightest pressure? Every week at Live Science, we call attention to a rare disorder that may not be widely known, describing its symptoms, treatments, causes and recent cases that caught our attention.
Latest about rare diseases
![A collage of four MRI brain scans in black and white (two images on top of two others) against a blurred background.](https://cdn.mos.cms.futurecdn.net/nHrzC9Q8AGtkkCQ3mVon3i-320-80.png)
The exceptionally rare disease that causes holes to form in your brain
By Emily Cooke published
Creutzfeldt-Jakob disease is an extremely rare and fatal brain-wasting disease that's like a human version of "mad cow."
![An illustration of a damaged strand of DNA against a black background. The damage can be shown in red.](https://cdn.mos.cms.futurecdn.net/wXXkNxuzrUgBeZnFgQnhhj-320-80.jpg)
People with this rare genetic condition can't repair damage to their DNA
By Emily Cooke published
LIG4 syndrome is an exceptionally rare disorder caused by a genetic mutation that prevents the body from repairing damaged DNA.
![The mid-section of a person is shown as they are sat on the toilet holding a roll of toilet paper.](https://cdn.mos.cms.futurecdn.net/jJvUibfxza7pTtRQb7pcEJ-320-80.jpg)
What is alkaptonuria? The rare disease that turns your pee black
By Emily Cooke published
Alkaptonuria is an unusual disorder caused by a defect in protein metabolism.
![A man wearing glasses and a black roll-neck jumper is shown being licked by his dog on the face.](https://cdn.mos.cms.futurecdn.net/cPe3zKruSFCjsFZwqvT3P4-320-80.jpg)
What is Capnocytophaga? How an innocent dog lick can trigger a fatal infection
By Emily Cooke published
Capnocytophaga infections in humans are rare, especially in historically healthy individuals, but when it occurs, the disease can be deadly.
![A picture of Paul Karason sat on a sofa while being interviewed on TV.](https://cdn.mos.cms.futurecdn.net/9xtvhANHMSwwdythwPNKd6-320-80.jpg)
Argyria: The rare disease that turns people blue
By Emily Cooke published
Argyria is caused by a buildup of silver in the body, which discolors the skin.
![Illustration of multiple cells of Francisella tularensis bacteria against a blurred, red background.](https://cdn.mos.cms.futurecdn.net/vQeNSnQtNDEQKXFqeMfVF9-320-80.jpg)
Tularemia: The 'rabbit fever' that can fatally infect humans
By Emily Cooke published
Tularemia, or "rabbit fever," is an infectious disease that normally affects animals but can spread to humans, sometimes via tick and deer fly bites.
![Black and white X-ray image of a person's chest. The heart is shown on the right-hand side of their chest.](https://cdn.mos.cms.futurecdn.net/ny8aeedVonjoEXFRzLHR3d-320-80.jpg)
Situs inversus: The condition where your organs are on the 'wrong' side
By Emily Cooke published
Situs inversus is a rare genetic condition that causes the organs in the chest and abdomen to be located on the opposite side from where they're usually found, like a mirror image.
![A close-up of tissue from an eye with frosted branch angiitis](https://cdn.mos.cms.futurecdn.net/6pw6GS8fmrN6wtvqEoiXWN-320-80.jpg)
Frosted branch angiitis: A rare eye condition that makes the retina look like a frosted tree
By Emily Cooke published
Frosted branch angiitis is a rare condition that makes the blood vessels that supply the retina look like the frosted branches of a tree.
![A woman in shown lying on her side in bed. She is awake and staring into the distance. Natural light appears to be streaming across her face.](https://cdn.mos.cms.futurecdn.net/vtUCQNsMc2ksudszqhigad-320-80.jpg)
Fatal familial insomnia: A genetic condition where people never sleep again
By Emily Cooke published
As fatal familial insomnia progresses, patients completely stop sleeping and enter a coma-like state that results in death within months.
![Composite image of four images of a young girl with Angelman syndrome. In two of the images she is facing she camera, in another she is side on to the camera and the other image shows her hands. Behind the composite image is a blurred, enlarged version if it.](https://cdn.mos.cms.futurecdn.net/pPZMfAKB9QTi5WF2Sj697h-320-80.png)
Angelman syndrome: A disorder that stops people walking and speaking
By Emily Cooke published
Angelman syndrome is a rare disease that disrupts the normal development and function of cells, particularly in the nervous system, leading to severe developmental delays and learning disabilities.
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