Rare and Orphan Diseases

What is a rare disease?

A rare disease is any medical condition that affects fewer than 200,000 people in the United States. Globally, the exact definition of a rare disease varies by country. For example, in the United Kingdom, rare diseases are those that affect fewer than 1 in 2,000 people. The World Health Organization (WHO) defines rare diseases as those that affect fewer than 65 in 100,000 people.

So far, researchers have identified over 7,000 rare diseases. Combined, they impact more than 25 million people in the U.S., and over 300 million people (often children) around the world.

If you’re living with a rare disease, you’re probably all too aware of numbers. You know your condition isn’t common. You know it’s lucky to find just one other person who understands what you’re going through. But you also know numbers don’t reveal the full picture. Rare diseases are also defined by their impact on people’s lives. For example:

• It can take years to get a diagnosis.
• Symptoms of a rare disease often mimic those of other conditions.
• Symptoms may make it hard to keep a job, manage household tasks or simply get through the day.
• Most rare diseases don’t yet have effective treatments.
• Rare diseases often lead to financial hardships for families.
• Living with a rare disease can be physically and mentally exhausting for individuals and caregivers.

Scientists are working hard to understand the causes of rare diseases and develop treatments. If a rare disease is affecting you or someone you love, take heart in knowing science has come a long way. And it’s continuing to push forward. Connecting with healthcare providers and patient support groups can help you gain information, support and hope.

What is an orphan disease?

Many people use the terms “orphan disease” and “rare disease” interchangeably. But there’s a slight difference. Orphan diseases are diseases (including rare ones) that researchers aren’t investigating much, or at all. This has often been due to cost.

But things are improving as new sources of funding open up for researchers. For example, governments and organizations around the world are ramping up their efforts to fund research into orphan drugs. These are medications that treat rare and orphan diseases.

What are some examples of rare diseases?

There are thousands of rare diseases, and researchers continue to discover new ones. Some names may be more familiar to you than others. Here are some examples of well-known, as well as lesser-known, rare diseases:

• Acromegaly.
• Alice in Wonderland syndrome.
• Amyotrophic lateral sclerosis (ALS).
• Aplastic anemia.
• Cystic fibrosis.
• Duchenne muscular dystrophy.
• Ehlers-Danlos syndrome.
• Fabry disease.
• Gaucher disease.
• Huntington’s disease.
• Mesothelioma.
• Maple syrup urine disease.
• Rocky Mountain spotted fever.
• Sickle cell disease.
• Tangier disease.

What causes rare diseases?

There are many different causes of rare diseases. Three main groups of causes include:

• Genetics. Gene mutations (changes) are a common cause of rare diseases. You might inherit a genetic mutation from a parent (germline mutation). Or the mutation might occur randomly without any family history (somatic mutation).
• Germs (microbes). Germs cause infections, and sometimes, these infections can be quite rare. Some infections are rare in the U.S. but common elsewhere (for example, tuberculosis).
• Toxins. Certain substances can harm your body and lead to disease. For example, exposure to asbestos can lead to mesothelioma, a rare lung condition.

Other possible causes include:

• Not getting enough of a certain vitamin or mineral (nutritional deficiency).
• Injuries.
• Unintended effects of treatment.

Sometimes, rare diseases occur with no known cause.

What are the symptoms?

Symptoms of rare diseases can vary widely according to the disease. Sometimes, rare disease symptoms mimic those of other, more common conditions. Some people have no symptoms early on.

See a healthcare provider if you have any symptoms of illness, such as pain or constant fatigue, and don’t know why.

How are rare diseases diagnosed?

Rare disease diagnosis is often challenging. This is because:

• Symptoms may resemble those of other medical conditions.
• Many diseases are so rare that healthcare providers don’t diagnose or treat them often. So, the disease can be hard to recognize.

It might take several years to learn what’s happening inside your body. Providers will ask you about your symptoms and run tests, like imaging tests and blood tests, to learn more. This process can be tiring and frustrating, and healthcare providers understand that. They’ll do whatever they can to reach a diagnosis and/or refer you to specialists who can find out more. For example, your usual provider may refer you to a medical center that specializes in diagnosing and treating rare diseases.

Rare disease diagnosis in babies

In the U.S., healthcare providers do routine screenings for newborns. These screenings help identify conditions a baby might have that aren’t immediately visible, like sickle cell disease or cystic fibrosis. Newborn screenings are an important way providers diagnose rare diseases in babies. An early diagnosis allows your baby to begin treatment right away.

What are the available treatments for rare diseases?

Possible treatments for rare diseases include:

• Medications.
• Nutritional supplements or changes to your diet.
• Occupational therapy.
• Procedures or surgeries.
• Physical therapy.
• The use of medical devices.

The goals of treatment differ by disease and may include:

• Curing the disease (this is rarely possible).
• Preventing the disease from getting worse.
• Managing symptoms.

Many rare diseases don’t yet have effective treatments. Researchers continue to investigate treatments that will help millions of people.

You may want to ask your healthcare provider about available clinical trials. Clinical trials are carefully designed research studies that allow researchers to see how well certain tests and treatments work. Joining a clinical trial can give you access to the latest, most promising treatments for your condition.

If you come across a “remedy” or “cure” online, proceed with caution. Show the site to a healthcare provider, and they can tell you if the product or treatment is worth pursuing or not. Some products might not do anything to help you, and some might even be harmful.

Can rare diseases be prevented?

There’s not much you can do to prevent rare diseases, especially as many are genetic. If you or your partner have a rare disease and you’re considering pregnancy, it may help to seek genetic counseling. Your counselor can explain the chances of your baby developing the disease.

What can I expect if I have a rare disease?

Your outlook, or what you can expect going forward, depends on:

• Your specific diagnosis.
• How early you receive a diagnosis.
• Available treatments.
• Other medical conditions you may have.

Your healthcare providers can tell you more based on these factors. Many people with rare diseases live long, happy lives. But unfortunately, rare diseases can sometimes cut a person’s life short.

Keep in mind that each person is different. Talking to others who have your condition can help you learn a lot, but your paths might go in different directions. For example, try not to get discouraged if treatment that helped someone else isn’t helping you. Your providers will continue working with you to find the best options in your unique situation.

When should I see my healthcare provider?

See a healthcare provider if you have new symptoms or changes in symptoms that don’t have a clear cause. If you’ve been to multiple providers and they can’t find a cause, you may want to ask for a referral to a medical center that specializes in diagnosing, treating and researching rare diseases.

What questions should I ask my provider?

Here are some questions that can help you learn more after getting a diagnosis:

• What caused my condition?
• What treatments are available to me, and what do they involve?
• What’s my outlook?
• Do you recommend taking part in a clinical trial?
• Do you recommend genetic testing for my family?
• Can you connect me with patient support groups?

Where can I find a rare disease list?

The National Organization for Rare Disorders (NORD) provides a rare disease database on its website. You can read about over 1,200 rare disorders, listed alphabetically. You can also search for a specific disease.