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Oral Health Topics

Hypophosphatasia and X-Linked Hypophosphatemia

Key Points

  • Hypophosphatasia is a rare, inherited metabolic disorder in which patients have deficient tissue nonspecific alkaline phosphatase (TNAP) enzymatic activity. Oral manifestations characteristic of various forms of hypophosphatasia can include early loss of deciduous teeth, severe dental caries, and alveolar bone loss.
  • In 2015, the U.S. Food and Drug Administration (FDA) approved a recombinant form of TNAP enzyme replacement therapy called asfotase alfa (Strensiq®, Alexion Pharmaceuticals, Inc.) for subcutaneous administration in patients with perinatal, infantile, and juvenile-onset forms of hypophosphatasia.
  • X-linked hypophosphatemia, also known as vitamin D-resistant rickets, is an inherited disorder characterized by low levels of phosphate in the blood due to abnormal processing in the kidney, leading to phosphate wasting and resulting in soft, weak bones (rickets).
  • In 2018, the FDA approved burosumab-twza (Crysvita™, Ultragenyx Pharmaceuticals, Inc.), a monoclonal antibody that inhibits activity of excess fibroblast growth factor 23, thereby restoring normal renal phosphate processing for adult and pediatric individuals with X-linked hypophosphatemia.
  • Introduction
  • Hypophosphatasia
  • X-Linked Hypophosphatemia
  • References
  • ADA Resources
  • Other Resources
Prepared by: Department of Scientific Information, ADA Science Institute
Last Updated: May 8, 2018


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