Illness and diseases are common in the US, but did you know there are some extremely rare diseases that only a few people develop?
What Is a Rare Disease?
In the USA, a rare disease is one that affects fewer than 200,000 people.
The Orphan Drug Act of 1983 defined the numbers and encouraged drug companies to “adopt” rare diseases with financial incentives.
People with extremely rare diseases are often left facing an incurable disease simply because the funding is not in place to discover more about the condition and potential treatments.
The Act was invoked to promote research into these unusual and often life-limiting diseases.
What Causes a Rare Disease?
There are several causes of a rare disease.
Many are caused by genetic mutations. These genetic changes can be inherited and passed on to children.
Other factors include infections, cancers, and environmental influences.
Although there are different ways for an extremely rare disease to develop, it’s common that they have no treatment, and people have to manage the symptoms as best they can.
Here are 20 of the rarest diseases in humans and their causes.
Top 20 Rare Diseases
Gigantism is an extremely rare disease that occurs when there’s too much growth hormone before the bone plates have fused.
The excess of growth hormone means muscles, organs, and bones grow to a larger-than-usual size. Gigantism can also cause delayed puberty, vision problems, and weakness.
It’s usually caused by a tumor in the pituitary gland, but sometimes genetic mutation plays a part. Treatment aims to block growth hormones through surgery, medication, and radiation therapy.
2. Maple Syrup Urine Disease
This is a rare genetic disease whereby the body cannot process certain amino acids. High levels of amino acids are dangerous, and this disease can be fatal.
Symptoms include sweet-smelling urine, lethargy, jerking, twitching, and delayed development.
It isn’t curable but can be treated through a low-protein diet.
3. Ochoa Syndrome
Ochoa syndrome is a rare disease that’s best known for the unusual facial expressions it creates. It’s also known as the hydronephrosis-inverted smile because instead of smiling, the sufferer frowns and scowls.
Urinary and bowel incontinence is a frequent symptom of Ochoa syndrome, as urine backs up into ducts and accumulates in the kidneys, potentially leading to kidney failure.
It’s caused by a genetic mutation and has no cure.
4. Foreign Accent Syndrome (FAS)
FAS is a speech disorder that causes a change in accent. It’s most commonly diagnosed after brain injury or disease such as multiple sclerosis.
It’s been documented across the world, with Brits sounding French and Americans sounding Spanish.
There’s no cure, but it’s not harmful.
5. Carcinoid Syndrome
Rarely, a carcinoid tumor leaks chemicals into the bloodstream and causes skin flushing, lesions, shortness of breath, and bowel changes.
The liver would usually flush out these toxins, but in severe cases, there is so much chemical it’s not possible to clear it all before it affects the organs.
Treating underlying cancer can reduce symptoms, but it can develop into carcinoid heart disease, which thickens heart valves and creates leaks that can be fatal.
6. Situs Inversus
This is a condition where a person is born with organs situated on the opposite side of the body. For example, the heart is on the right, or the heart is below the stomach.
Situs Inversus has been traced through family lines but doesn’t usually require treatment.
7. Wilson’s Disease
We need minute amounts of copper to keep cells healthy, but when there’s an excess of copper in the tissues, it’s dangerous.
Wilson’s disease is a genetic disorder whereby sufferers have too much copper in their systems.
Early symptoms include jaundice, fluid retention, weight loss, and fatigue, but some don’t realize they have it until they develop sudden liver failure.
There is no cure for Wilson’s disease, but it can be managed through medication and dietary restrictions.
8. Stiff Person Syndrome
This syndrome is an extremely rare progressive disease that causes spasms, rigidity, and muscle stiffness.
It’s the result of an autoimmune condition on the nervous system. Sometimes spasms are so strong that they cause bone fractures and limit mobility.
Stiff person syndrome isn’t curable but can be managed with muscle relaxants, physiotherapy, and exercise.
9. Cyclic Vomiting Syndrome
This is a cycle of consistent vomiting that can last for days before disappearing for a period of time.
During the vomit-free cycle, sufferers can live a normal life, but the vomiting phase is debilitating, and dehydration can be a problem. In severe cases, hospitalization is necessary.
There’s no permanent cure, but people can grow out of it over time.
10. Peeling Skin Syndrome
With this genetic disorder, skin reddens, itches, and peels off.
Experts don’t know why it occurs, and autoimmune drugs have not helped in studies undertaken so far.
Peeling skin syndrome is inherited in many cases and could be the result of a genetic mutation. There is no cure, but keeping skin moisturized and free from infection helps manage the condition.
ACDC stands for Arterial Calcification Due to Deficiency of CD73. It causes calcium to accumulate painfully in the large blood vessels of the hands and feet and in arteries below the waist.
This is an extremely rare disease caused by a gene mutation. Only nine people in the US are known to have it.
12. Black Hairy Tongue
This disease is rare but fortunately curable.
Hairy tongue is created by an excess growth of protein called keratin. It can make the tongue look as if it has a black, hairy texture. Halitosis, gagging, and tickling sensations are common.
This is an unsightly and distressing condition but is easily treated with antibiotics.
13. Eagle Syndrome
Pain, difficulty swallowing, tinnitus, and the feeling something is stuck in your throat could be due to a rare disease known as Eagle Syndrome.
It’s characterized by recurrent pain in the middle of the face and throat and can appear after tonsillectomy or throat damage.
This is due to a calcified stylohyoid ligament that anchors larynx and tongue muscles in place.
Eagle Syndrome is treated with surgery and painkillers and can be cured in the majority of cases.
Progeria is an extremely rare congenital disease that causes children to look as if they are aging prematurely.
Wrinkles, hair loss, and abnormal facial developments are common symptoms. The child is likely to suffer a heart attack or stroke before they reach age 13, as their arteries tend to weaken.
There is no cure for this poorly understood rare disease.
15. Adiposis Dolorosa
This is the result of numerous fatty growths that occur rapidly across the body.
Growths range from small in size to large, and the condition is twice as common in women. Other symptoms include fatigue, memory problems, pain, and mobility issues.
It’s not known why adiposis dolorosa occurs, and there’s no cure—although surgical removal of large growths can help mobility.
16. Fragile X Syndrome
Fragile X syndrome is a genetic abnormality that creates developmental problems, including delayed speech, anxiety, autism spectrum conditions, and a long, narrow face with a prominent jaw and forehead. Men are more likely to be affected than women.
There’s no cure, but symptoms can be managed with supportive care.
Morgellons is a rare disease that makes sufferers think they are experiencing stings, biting, and crawling sensations.
Skin can appear red, black, and blue with accompanying memory loss, joint pain, and visual disturbances.
It’s thought only 14,000 people have Morgellons. Treatment is difficult, and some experts believe it’s actually a psychological disease.
18. Water Allergy
An extremely rare disease is an allergy to water.
Only 30 people have ever been recorded as having an allergy to water. It’s thought to be caused by fluctuating hormones after giving birth that become sensitive to ions in water.
Sufferers are left unable to drink water, bathe, or go out in the rain without developing a painful, burning rash.
19. Fibrodysplasia Ossificans Progressiva (FOP)
FOP is a progressive disease that turns tendons into bone.
It’s a congenital disease diagnosed at birth by a malformed big toe. The condition can speed up after an accident or viral illness, leaving the affected area with bone growth.
FOP is a genetic mutation. As the disease progresses, people are stiffened by bone growths and lose mobility.
There is no cure, although corticosteroids can help prevent ossification after muscle trauma.
20. Alice in Wonderland Syndrome
Named after Lewis Carroll’s famous book, Alice in Wonderland Syndrome is when people perceive objects as much smaller than they are. It’s also known as micropsia or Lilliput sight.
It’s thought this is a symptom of migraine headaches and may respond to migraine medications.
Extremely Rare Diseases Are More Common Than You Think
There are 7,000 identified extremely rare diseases, and it’s thought that 25–30 million Americans have one.
Although the instances of each rare disease are very small, the combined total is large.
It turns out that rare diseases are more common than you might expect.