Bones, Hypophosphatasia, Sibling

Hypophosphatasia is a skeletal dysplasia affecting the gene ALPL, which codes for tissue non-specific alkaline phosphatase. As alkaline phosphatase is responsible for the mineralization of the skeleton, any detrimental changes to its structure and function will delay skeletal development.

This disease is characterized by widespread non-ossification of the skeleton, leading to brittle bones and fracturing in utero. The presence of Bowdler spurs help to differentiate hypophosphatasia from other disorders of ossification.

This is a radiograph of the main subject's sibling with the same mutation, but far less affected; included to illustrate the the disease's wide spectrum of severity.

See related content for radiographs and specimen photographs of the main subject.