It is estimated there are between 6,000 to 8,000 types of rare diseases in the world. Some diseases are so rare that there have been only a handful of cases ever documented. Nevertheless, they are estimated to affect between 6 to 8% of the world’s population, or 545 million people.

While around 75% of rare diseases affect children, with 30% of patients not surviving past the age of 5; sometimes due to a lack of or inaccurate diagnosis and/or treatment – many do not present symptoms until the onset of adulthood.1

The term “rare disease” is defined differently from country to country. In general, a disease is considered rare if it affects up to 1 in 2,000 people.

Currently in Hong Kong there is not sufficient information on prevelancy rates of rare diseases to generate meaningful estimated figures.

1. Source: European Organization for Rare Diseases