The Central Registry of Rare Diseases (CRRD) is a national database containing a minimal, pseudonymised, cross-sectional dataset on patients who have consulted an expert centre in Belgium for a rare disease. The registry includes patients with a confirmed rare disease diagnosis, as well as patients for whom all reasonable diagnostic efforts by rare disease experts, using state-of-the-art methods and available diagnostic capabilities, did not result in a conclusive diagnosis of a clinically recognised condition.
