What is the most rare disease ever?
From affecting around 100 people to just one person, these are among the rarest diseases in the world.
- RPI deficiency.
- Fields Condition.
- Hutchinson-Gilford Progeria.
What are the top 10 rarest diseases?
Top 10 Rarest Diseases You’ve Never Heard Of –
- 10: Foreign Accent Syndrome. 
- 9: Microcephaly. 
- 8: Epidermodysplasia Verruciformis. 
- 6: Hutchinson-Gilford Progeria Syndrome. 
- 5: Harlequin-Type Ichthyosis. 
- 4: Congenital Analgesia. 
What are the 7000 rare diseases?
You can find a list of all the 7,000+ rare diseases on the Orphanet website.
- Fibrodysplasia ossificans progressiva. Prevalence: roughly 1 in 2,000,000.
- Ehlers Danlos syndrome. Prevalence: Unknown.
- Tyrosinemia type 1. Prevalence: Unknown.
- Duchenne muscular dystrophy.
- Cystic fibrosis.
- NGLY-1 deficiency.
How many rare diseases are there?
Rare Diseases FAQ. A rare disease is generally considered to be a disease that affects fewer than 200,000 people in the United States at any given time. There are more than 6,800 rare diseases. Altogether, rare diseases affect an estimated 25 million to 30 million Americans.