Intact Fibroblast Growth Factor 23 (FGF23), Serum
Also known as: IFGF23
Use
This test may assist in the evaluation of inherited or acquired disorders of mineral metabolism such as hypophosphatemic rickets, tumor-induced osteomalacia, and familial tumoral calcinosis with hyperphosphatemia. Elevated levels of Intact FGF23 are commonly seen in conditions like X-linked hypophosphatemia (XLH) and tumor-induced osteomalacia (TIO), although normal levels may also be observed. This test is particularly useful for identifying patients suspected of having XLH when Intact FGF23 concentrations exceed 22 pg/mL.
Special Instructions
Not provided.
Limitations
Should be interpreted in conjunction with serum phosphate measurements. Intact FGF23 levels may not be indicative of all conditions influencing mineral metabolism. This test is not cleared or approved by the FDA and, if ordered as a tumor marker, results should not be considered conclusive for the presence of malignant disease. Elevated or normal Intact FGF23 levels should also be evaluated with consideration to the individual’s normophosphatemic status.
New York Approved
Methodology
Immunoassay (CLIA)
Biomarkers
FGF23
Protein
LOINC Codes
- 54390-0 - FGF-23.intact SerPl-mCnc
Result Turnaround Time
6-11 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.25 mL
Container
ARUP standard transport tube
Collection Instructions
Collect in a serum separator tube (SST) or plain red tube. Transfer to ARUP transport tube.
Storage Instructions
Frozen. Refrigerated is also acceptable.
Causes for Rejection
Ambient conditions unacceptable
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | 2 weeks |
| Frozen | 3 months |
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