Forgotten Diseases Research Foundation

New! A Free Tool to Help Understand Rare Diseases

The FDRF is pleased to release a beta version of a free online analysis assistant. This tool is substantially different from any other software we have seen, in that it is the first tool we're aware of that provides a quantitative way to compare different diseases. We have funding that will help us expand this tool from the basic one that it is now into something more sophisticated. There are currently 74 different diseases in the database. Information about each one has been characterized by hand, from published case histories (there is no private information in this database). Hand characterization is slow, but it allows us to provide high quality, carefully curated data.

Instructions. The tool is easy to use. Simply select the conditions you want to compare and click OK. The software will return a score between 0 and 1, and it will list all clinical features shared by the conditions you choose. Higher scores mean closer similarity. For example, the score for Ataxia-telangiectasia (classic form) and Ataxia-telangiectasia (mild form) is 0.863. This score is the highest in the database. The score between Ataxia-telangiectasia (mild form) and narcolepsy is 0.009.

You'll also see numbers next to shared symptoms (60, 35, ..., down to 2). These numbers refer to how common a given feature is in a given condition, and are used for other purposes. They appear here because of the beta nature of the software. As an example, 60 means that the feature occurs in almost all patients with a given disease, while 2 means it occurs in very few patients.

You may access the tool here. Please don't compare more than about 10 diseases at once, as this will make our server feel unhappy.

A Free Tool to Help Diagnose Rare Diseases

The FDRF is pleased to release a beta version of our free online diagnosis assistant. Our tool is different from other online systems that help diagnose rare diseases, in that we've designed it to mimic an expert clinician. The tool asks questions about different signs and symptoms of diseases and uses a proprietary method for matching symptoms with a disease. Information about each disease in our database has been characterized by hand, which allows us to provide carefully curated data for the tool to use.

To use the tool, simply answer yes, no, or don't know as applicable. Try to be as accuarate as possible, especially if you don't know the answer to a question. All answers (yes, no, and don't know) are used by the software when it makes decisions. This tool takes up to 10-15 minutes to provide answers, but we believe that the results it provides are more accurate than those provided by tools that simply ask you to type in some symptoms.

You may access the tool here.

We're always adding new diseases to the tool. Upcoming conditions include more types of osteogenesis imperfecta. Please contact us at vnatale AT forgottendiseases dot org with any questions or comments.

A Compendium of Information on Rare Diseases

Hover over any photo or painting for more information.

This page has links to information about rare diseases in our diagnosis tool's database. Our entries focus primarily on information that will help with diagnosis, but there is also information about treatments, clinical trials, gene mutations, and other occasional miscellany that we have found or learned ourselves. There are also numerous links on each page: we strive to find information about worldwide support groups, testing facilities, and scholarly publications about each disease. We have also begun to post links to videos and other multimedia sources that can help a site user learn more about a given disease. These links typically include videos of patients and patient photograph galleries.

We try to make our information as accurate as possible. Therefore, the information on these pages comes from peer-reviewed case histories or reviews of a given disease. However, please remember that the information here can't subsitute for advice from a medical professional. If you have concerns about someone's growth, you should consult a doctor.

Alphabetical list of conditions







Please remember that the information presented here cannot take the place of advice from a physician. If you have any questions or concerns about your health or the health of someone in your family, talk to a physician.


Pages on this site were authored and edited by Valerie Natale, PhD, Shannon Long, PhD, and Anuradha Rajagopalan, MS. All authors are life/biomedical scientsists and use peer-reviewed sources for material presented here, as is noted by the references on each page. The content is regularly reviewed and updated.

Page last modified on 2 March 2021.