Rare Diseases Europe (EURORDIS)
An alliance representing over 600 rare disease patient organizations in 58 countries. EURORDIS is committed to empowering patient groups and raising awareness of rare diseases.

Office of Rare Diseases Research (ORDR)
Part of the National Institutes of Health (NIH), this site provides information on HPP as well as the opportunity to ask a specialist questions about your experiences with HPP.

MAGIC Foundation
Provides support and education to families of children with growth disorders and affected adults with endocrine disorders.

Osteogenesis Imperfecta (OI) Foundation
OI, a genetic bone disorder in which fragile bones break easily, is different from HPP. However, OI and HPP share many symptoms. The OI Foundation is dedicated to research, education, awareness, and support for healthcare professionals, families, and patients with OI.