- National Organization for Rare Disorders, Inc.
- Information about NORD, its programs, special events and the variety of services offered. Includes a rare disease, organization and orphan drug database. Diseases are listed alphabetically for easy searching. - Cherubs - A non-profit support group for the families and medical care providers of children and adults born with Congenital Diaphragmatic Hernia.
- Contact a Family - Information about this organization as well as the CaF directory of specific conditions and rare disorders. Also details about the Rare Disorders Alliance - UK.
- Fibrous Dysplasia Support Online - For those seeking support and information concerning the rare bone diseases: fibrous dysplasia, McCune Albright Syndrome and Cherubism.
- Human Growth Foundation - Information about growth-related disorders through education, research, and advocacy. Member driven organization.
- Information Centre for Rare Diseases and Orphan Drugs - Offers an Internet portal. Includes news, forums, rare disease and orphan drug info and registration forms
- Kindler Syndrome - An article and case study of this rare disease. Includes links.
- Lymphangiomatosis and Gorham's Vanishing Bone Disease - Provides general information and a personal account, including pictures and X-rays. Also offers patient contact and an email discussion group.
- Nomid /Cinca - Resource for parents and patients suffering from Neonatal Onset Multi-inflammatory Disease Chronic, or Infantile, Neurologic, Cutaneous and Articular syndrome. Site maintained by patients, parents and friends for their counterparts worldwide. Email support group at eGroups.
- Office of Rare Diseases - Information on more than 6000 rare diseases, including current research, publications from scientific and medical journals, completed research, ongoing studies, and patient support groups.
- Tetrahydrobiopterin - Information on structure, biosynthesis and pathophysiology of BH4 and tetrahydrobiopterin deficiency.