Hypophosphatasia

Disease Overview

Hypophosphatasia (HPP) is a genetic condition that causes abnormal development of the bones and teeth. The severity of HPP can vary widely, from fetal death to fractures that don’t begin until adulthood. Signs and symptoms may include poor feeding and respiratory problems in infancy; short stature; weak and soft bones; short limbs; other skeletal abnormalities; and hypercalcemia. Complications can be life-threatening. The mildest form of the condition, called odontohypophosphatasia, only affects the teeth.[201] HPP is caused by mutations in the ALPL gene. Perinatal (onset before birth) and infantile HPP are inherited in an autosomal recessive manner. The milder forms, especially adult forms and odontohypophosphatasia, may be inherited in an autosomal recessive or autosomal dominant manner.[10516] While treatment has always been symptomatic and supportive, recently an enzyme replacement therapy (ERT) called asfotase alfa has been show to improve bone manifestations people with childhood onset HPP and has been approved by the FDA.[10514][10515]

Synonyms

• Phosphoethanol-aminuria
• Hypophosphatasia mild
• Phosphoethanolaminuria
• Rathburn disease