NAR Molecular Biology Database Collection entry number 145
Sabbagh, Y., Tenenhouse, H.S.
McGill University Health Center, Montreal Children's Hospital Research Institute Montreal, Quebec, Canada

Database Description

PHEXdb is a relational locus-specific database for mutations in the PHEX gene. The latter are responsible for X-linked hypophosphatemia (XLH) (OMIM 307800), a dominant disorder of phosphate homeostasis characterized by growth retardation, rachitic and osteomalacic bone disease, hypophosphatemia, and renal defects in the reabsorption of filtered phosphate and the metabolism of vitamin D. Upon its creation in April 1999, PHEXdb listed 86 mutations. As of December 2003, a total of 171 different mutations in the PHEX gene have been entered. PHEXdb allows online access where users can search the database by mutation, which includes name and type of mutation, and codon name; by phenotype, which includes inheritance (X-linked or sporadic) and clinical and biochemical phenotype; and by authors who published or submitted mutations. In addition, in vitro expression analysis and catalytic activity using a fluorogenic synthetic peptide of some characterized mutants are found in the tables. PHEXdb also provides a submission form that will allow newly identified mutations in the PHEX gene to be added to the database. The PHEXdb homepage includes links to information pages such as the Online Mendelian Inheritance in Man ( and the XLH Network page (, and references to publications on PHEX, XLH and mouse homologues (Hyp and Gy). PHEXdb serves as a communication link between researchers whose goal it is to elucidate PHEX function and define its role in pathogenesis of XLH. This resource will help to document genotype/ phenotype correlations. It is noteworthy that all the mutations present in the PHEX database have been submitted to the Human Genome Variation Database (, a database that regroups all the mutations that have been identified in the human genome.


1. Sabbagh Y, Jones AO, Tenenhouse HS. PHEXdb, a locus-specific database for mutations causing X-linked hypophosphatemia. Hum Mutat. 2000;16(1):1-6.

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