GENE REFERENCE / HGNC:8918

PHEX

phosphate regulating endopeptidase X-linked

protein-coding geneXp22.11Gene information

What does this gene do?

The PHEX gene provides instructions for making the PHEX enzyme, which appears to be important for the proper development of the bones and teeth.

Studies suggest that the PHEX enzyme affects the activity of fibroblast growth factor 23, which is a protein that helps regulate phosphate levels within the body. Phosphate is a mineral that plays a critical role in the formation and growth of bones during childhood and helps maintain bone strength in adults. Fibroblast growth factor 23 works within the intestines and the kidneys to keep the body’s phosphate levels in balance.

The PHEX enzyme may also be involved in the process that deposits minerals into developing bones and teeth (mineralization). Mineralization is critical for the formation of bones that are strong and rigid and teeth that can withstand chewing and grinding. The PHEX enzyme may interact with molecules that play a key role in regulating bone mineralization.

Researchers are working to learn more about the various functions of the PHEX enzyme and its interaction with fibroblast growth factor 23.

Source: MedlinePlus, National Library of Medicine. Source publication: 2026-02-13. Source review: 2026-02.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
X-linked dominant hypophosphatemic ricketsMONDO:0010619 · Evaluated 2025-05-15	X-linked	DefinitiveTubulopathy Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles: 1,919
Submissions for variants in or overlapping this gene: 2,752
Submissions explicitly reporting this gene: 2,482
Alleles reported pathogenic / likely pathogenic: 1,016
VariationIDs with uncertain significance: 309
VariationIDs with conflicting classifications: 65

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about PHEX?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 1,016 alleles in PHEX reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in PHEX.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

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