The frequently given answer to the question ‘What proportion of rare diseases is genetic?’ is ‘80%’. But where does this statistic come from?
To illustrate the extent of the problem, the Wikipedia page for rare diseases currently mentions the “80% are genetic” statistic twice. Once with a “citation needed” warning, and once with a link to a webpage that is no longer available.
I used Google, Google Scholar, and the Internet Archive to try to find the first time the statistic was given. Some mentions cite the book, The NORD Guide to Rare Disorders, published in December 2002. But I also found it in a company’s press release from April 2002, again mentioned without any source attribution, and presented as an unequivocal fact.
Our investigations lead us to believe that the statement “80% of rare diseases are genetic” should probably be considered folklore rather than fact. If anyone can provide evidence otherwise, or can provide the provenance of the statement please contact us. We would be delighted to find out.
Currently, it seems that it is not known what proportion of rare diseases are genetic. Moreover, it is not easily knowable, because the definition of rare disease is unclear and the cataloguing of rare diseases is not comprehensive.
The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion, and analysis. Read full, original post: How many rare diseases are genetic?