Medical Definition of Hypophosphatasia

  • Medical Author:
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Hypophosphatasia: a rare genetic disorder that causes abnormal development of the teeth and bones. The abnormality is related to faulty mineralization, the process by which bones and teeth become strong due to their uptake of minerals like calcium and phosphorus. There are different forms of hypophosphatasia that vary in severity. The most severe form can cause stillbirth, while the mildest form results in the early loss of deciduous (baby) teeth without bone abnormalities. Hypophosphatasia is caused by mutations in a gene known as the tissue nonspecific alkaline phosphatase (ALPL) gene, also referred to as the TNSALP gene. Depending on the form of the condition, it can be inherited in both an autosomal dominant (meaning only one parent must carry the defective gene) or an autosomal recessive (meaning an affected person must receive a defective copy of the gene from each parent) pattern. Males and females are equally affected.

Reviewed on 9/7/2018

REFERENCE: National Organization for Rare Disorders. Hypophosphatasia. Updated 2017.

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