- Canadian Opitz Family Network - A description of Opitz G/BBB Syndrome.
- Family Village - Opitz G Syndrome information and contact links.
- National Library of Medicine: OS - Opitz syndrome, the synonyms, a summary and a list of major features.
- NORD: Opitz Syndrome - A look at the alternate names, a general discussion and resources.
- Zach's Opitz Syndrome Site - Offers information, a family's experience with this syndrome and links to the Opitz Family Network.