What is a rare disease?

Mia - Meet our patients - Centre for Children’s Rare Disease Research

Rare diseases are life-threatening or chronically debilitating diseases which, when grouped together, are more common than you may think.

This means that diagnosis of rare diseases is often difficult and delays may occur. They often leave patients and their families feeling isolated and vulnerable.

As a group, rare diseases are not uncommon and when taken together, they affect a great many people. Unfortunately 75 per cent of rare diseases affect children and very sadly 30 per cent of patients with rare diseases will die before their fifth birthday.

About 80 per cent of rare diseases are of a genetic basis and others include rare cancers, diseases of the immune system, birth defects and infectious diseases. The European Union’s definition of a rare disease is one that affects fewer than five in 10,000 people and some well-known rare conditions include cystic fibrosis and muscular dystrophy.

Only a quarter of rare diseases have had their molecular basis defined and some diseases are so rare that an average GP will only see a case once in their lifetime. The situation is critical, and the answers lie in medical research. The new centre will give us an unrivalled opportunity to urgently help those affected.

Image: Mia was born with a rare abdominal wall defect.