A Revised Classification of Primary Iron Overload Syndromes

Area of Science:

• Biochemistry and Molecular Biology
• Genetics and Genomics
• Hematology

Background:

• Hepcidin25 (Hep25) and ferroportin (FP) are key regulators in iron metabolism.
• Primary iron overload syndromes (PIOSs) were previously classified in 2012 based on the Hep25/FP system.
• Accumulated evidence necessitates a renewal of the PIOS classification.

Purpose of the Study:

• To renew the classification of primary iron overload syndromes (PIOSs).
• To integrate new molecular discoveries into the PIOS framework.
• To provide an updated diagnostic and therapeutic guideline for PIOSs.

Main Methods:

• Retrospective review of the 2012 PIOS classification.
• Integration of new data on hepcidin25 (Hep25), ferroportin (FP), and erythroferrone.
• Analysis of molecular mechanisms underlying different PIOS subtypes.

Main Results:

• Iron-loading anemia included as a prehepatic PIOS due to erythroferrone-induced Hep25 suppression.
• Traditional FP disease (FP-D) remodeled as the BIOIRON proposal.
• Hepatic PIOSs encompass four HC genotypes with reduced Hep25 synthesis; posthepatic PIOSs involve mutant FP resistance to Hep25.

Conclusions:

• The revised PIOS classification incorporates novel molecular insights.
• Updated classification aids in understanding and managing diverse iron overload conditions.
• The renewed classification is proposed for worldwide clinical utility.