Hypophosphatasia (HPP) is a rare inherited bone disease which affects approximately 1:100,000 people.
HPP is defined by a missing enzyme known as tissue non-specific alkaline phosphatase (TNSALP) which helps calcium and phosphate to be integrated into bone. It is also found in many other tissues in the body. The gene that codes for the enzyme is the TNSALPgene. The missing enzyme leads to calcium and phosphate building up in the body, and in severe forms this causes high serum levels of calcium and phosphate as well as kidney calcification (nephrocalcinosis).
Also, other metabolites that build up are strong inhibitors of bone formation which means that bone, and teeth, cannot be made properly. This causes fractures, bone pain as well as dental abnormalities.
There are five different forms of this condition:
Severity of Hypophosphatasia varies greatly. In general, the more severe forms are the ones that present earlier in life and develop over time, whereas the milder forms present later.
Children Living with Inherited Metabolic Diseases (CLIMB) is the United Kingdom's foremost provider of free metabolic disease information to young people, adults, families, professionals and other interested groups. CLIMB holds information on all forms of HPP and offers impartial advice and support to families and professionals worldwide. Our Family Contact Network enables us to put families in touch with each other to share experiences and reduce isolation. As part of our work, we endeavor to raise awareness of HPP throughout the medical profession and the general public to ensure a greater understanding of the condition.
HPP varies in severity and in presentation and each case is different, even within the same family. Even so, the treatment currently for all forms of HPP is merely symptomatic and supportive and at present there is no cure. However, following trials, enzyme replacement therapy looks a promising option for the future and CLIMB is proud to be able to link in with specialists and pharmaceutical companies from across the globe to bring you the latest updates on any new developments and research.
CLIMB can also offer information on associated bone disorders such as McCune-Albright Syndrome. Please contact us for further information.
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