Fibroblast Growth Factor 23 - Intact, Plasma

Test Overview

Clinical Utility

Fibroblast growth factor 23 or FGF 23 is a protein, which is encoded by the FGF23 gene in humans. FGF23 is a member of the fibroblast growth factor (FGF) family which is responsible for phosphate and vitamin D metabolism. The main function of FGF23 seems to be the regulation of phosphate concentration in plasma. FGF23 acts on the kidney, where it decreases the reabsorption and increases excretion of phosphate.

Method

Chemiluminescence (CL)

Analytical Platform

Diasorin Liaison XL

Result Included

Intact Fibroblast Growth Factor 23

Aliases/Synonyms

FGF23

Specimen

Specimen Type

Plasma

Containers

Collection Containers

Lavender top (EDTA)

Volume

Sample Volume

1.0 mL

Collection & Handling

Handling Information

Centrifuge and separate as soon as possible. Store and send frozen.

Performance & Interpretation

Turnaround Time

1 month

Results

Fibroblast Growth Factor 23

pg/mL

< 96

Comment

FGF23 concentrations must be interpreted in conjunction with plasma phosphate measurements and urinary fractional excretion of phosphate. Do not interpret FGF23 concentrations as absolute evidence of the presence or the absence of tumor induced osteomalacia. Patients receiving burosumab should not be monitored using the IFGF 23 assay.

Referral Location

Canada

Interface & Setup

HL7 Interface Codes

Order Code	Result Name	Result Codes	Units
FGF23UHN P	INTACT FIBROBLAST GROWTH FACTOR 23	64526	pg/mL

Test Version

Last Updated

2025-10-21

Fibroblast Growth Factor 23 – Intact, Plasma