Skip to content
HomeLatest newsHealth & wellnessWhat is a rare disease?
An illustration of a crowd of people, all in black and white, with one person in the center wearing a red top and blue pants.

What is a rare disease?

It’s estimated that over 300 million people around the globe are living with a rare disease. For Rare Disease Day, here’s what to know.

Share Article
share to

Rare diseases haven’t always received the attention they deserve because they affect relatively few people.

What makes a disease rare is how prevalent it is—that is, the number of individuals living with it. In the United States, a rare disease is one that fewer than 200,000 people live with. (In other words, 60 per 100,000 individuals.)
Around the world, rare diseases are identified and addressed differently. The European Union considers a disease rare if it affects no more than 50 per 100,000 people. The World Health Organization, on the other hand, defines a rare disease as one that strikes fewer than 65 per 100,000 people.

A rare disease is often genetic; 72% of rare diseases analyzed by researchers in a 2019 paper published in the European Journal of Human Genetics were found to have a genetic origin.

It can often take years for a person to be properly diagnosed with a rare disease, and about 95% of rare diseases do not yet have treatments.

Other rare diseases could be the result of an infection or allergy. In many cases the exact cause is unknown. Some cancers are also rare diseases.

Rare diseases tend to appear in childhood. Approximately two-thirds of those living with a rare disease are children. They are, unfortunately, usually incurable. About 95% of all rare diseases do not yet have treatments, according to the National Organization of Rare Diseases.
“Rare diseases are a global health priority,” says Carina Righetti, Director of the Janssen Pharmaceutical Companies of Johnson & Johnson’s Global Market Access and Policy, Rare Diseases. “People living with a rare disease deserve accurate diagnosis and timely access to treatment just as people with more prevalent conditions do.”

While living with any illness or disorder is a challenge for patients, families and caregivers, people with a rare disease have a harder time getting a diagnosis and treatment. It can often take years for a person to be properly diagnosed. These challenges extend to rare disease research and development.

“Improved rare disease awareness, sustained scientific innovation and public policies that support research and development and patient access to new therapies allow us to work together to transform the lives of patients with rare diseases,” notes Righetti.

Johnson & Johnson is working to tackle these challenges by diving deeper into research with the aim of developing new, transformational medicines that address unmet needs for these patients. These efforts span many disease areas including multiple myeloma, hemolytic disease of the fetus and newborn, AL amyloidosis, rare retinal diseases, pulmonary arterial hypertension and others.

Patients living with the roughly 7,000 rare diseases identified so far have also helped build awareness and encouraged action—such as by establishing the first annual Rare Disease Day on February 28, 2008.

Are you living with a rare disease?

See if you might be eligible to participate in a study that could potentially help lead to more effective treatment.

More from Johnson & Johnson

What to know about We All Belong: 2023 DEI Impact Review

The annual report details how Johnson & Johnson is harnessing the power of diversity, equity and inclusion to provide better care around the world.

Giving the gift of sight

In Kenya, around 1.5 million people—including children—contend with visual impairment or blindness. Sight For Kids, Johnson & Johnson’s global eye-care partnership, is devoted to changing these stats, one vision screening at a time.

Inside the development of a revolutionary treatment for blood cancers

In 2014, a Johnson & Johnson therapy gained approval for the treatment of a type of B-cell malignancy—increasing survival rates and changing the way scientists approach cancer treatment. These 8 milestone moments tell the transformational story.
You are now leaving The site you’re being redirected to is a branded pharmaceutical website. Please click below to continue to that site.