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FRRS1L

ferric chelate reductase 1 like

Chromosome 9q31.3 HGNC:1362 Tier C
FRRS1L 9q31.3 p arm q arm 9

FRRS1L is located on the long (q) arm of chromosome 9, at band 9q31.3. Arm ratio per GRCh38 - banding schematic.

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Clinical tests that include this

Overview

FRRS1L (ferric chelate reductase 1 like) is located on chromosome 9 and encodes a protein predicted to function in iron reduction processes. Iron metabolism is essential for numerous cellular activities, including oxygen transport, energy production, and DNA synthesis. Whilst the gene's name suggests a role in converting ferric iron to its ferrous form, experimental validation of this function in human tissues remains limited. Understanding FRRS1L may contribute to broader knowledge of how cells regulate iron availability, though clinical significance of variants in this gene has not been firmly established.

What the gene does

The FRRS1L protein is predicted to possess ferric chelate reductase activity, meaning it may catalyse the reduction of iron from its oxidised ferric state to the more readily absorbed ferrous form. This type of enzymatic activity is important for maintaining cellular iron homeostasis, as cells require iron in specific oxidation states for different biochemical processes. Iron serves as a cofactor for enzymes involved in mitochondrial respiration, DNA replication, and oxygen binding in haemoglobin. The precise tissues where FRRS1L is most active and the specific cellular compartments it operates within have not been comprehensively mapped. Current knowledge about this protein derives largely from computational predictions based on amino acid sequence homology to other reductase enzymes, rather than from direct functional studies in human cell systems.

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Chromosome location

FRRS1L is located on the long arm of chromosome 9 at position 31.3, designated cytogenetically as 9q31.3. This chromosomal region contains multiple genes and is positioned roughly in the middle third of chromosome 9's long arm. The gene's exon-intron structure and total transcript length have been documented in genomic databases, though detailed structural annotations remain incomplete compared to more extensively studied genes.

Protein structure

Domain architecture has not been experimentally characterised in detail for this protein. Whilst sequence analysis suggests the presence of regions consistent with reductase activity, specific functional domains have not been mapped through structural biology techniques such as crystallography or cryo-electron microscopy.

Domain map · 293 amino acids
DOMON (119–234)DOMON119–2341~147293
Domain - independent functional unit
🧬 Explore 3D structure on AlphaFold
UniProt:Q9P0K9Length:293 aaStructure:AlphaFold

Key variants

Genetic variants in FRRS1L have been identified through sequencing studies, though the clinical interpretation of most changes remains uncertain. Unlike genes with well-established disease associations, FRRS1L variants are not routinely classified as pathogenic or benign based on extensive patient cohort data. Research is ongoing to determine whether specific sequence changes affect protein function or contribute to disease phenotypes.

The table below shows the top 10 pathogenic or likely-pathogenic variants currently classified in ClinVar for FRRS1L.
View all on ClinVar →

Sample of pathogenic variants

10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.

Variant (HGVS) Protein change Classification Evidence Associated condition
c.246dup
Duplication
p.Phe83fs Pathogenic/Likely pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.283dup
Duplication
p.Ile95fs Pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.486C>A
single nucleotide variant
p.Cys162Ter Pathogenic/Likely pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.517C>T
single nucleotide variant
p.Gln173Ter Pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.566del
Deletion
p.Pro189fs Pathogenic/Likely pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.583G>T
single nucleotide variant
p.Gly195Ter Pathogenic/Likely pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.584_586del
Deletion
p.Gly195del Pathogenic/Likely pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.721C>T
single nucleotide variant
p.Arg241Ter Pathogenic/Likely pathogenic ★★☆☆ FRRS1L-related disorder
c.-78G>T
single nucleotide variant
- Pathogenic/Likely pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37
c.808C>T
single nucleotide variant
p.Gln270Ter Pathogenic ★★☆☆ Developmental and epileptic encephalopathy, 37

Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.

Associated conditions

No specific inherited conditions have been definitively linked to FRRS1L variants in clinical literature. The gene is not currently associated with a recognised Mendelian disorder, and it does not appear on NHS clinical gene panels for diagnostic testing. Future research may clarify whether variants in this gene contribute to complex traits or rare presentations that have not yet been fully characterised.

No disease links recorded for this gene in our reference set.

UK clinical status

Frequently asked questions

What does FRRS1L stand for?

FRRS1L stands for ferric chelate reductase 1 like. The name reflects the protein's predicted similarity to enzymes that reduce ferric iron to ferrous iron, though this function has not been fully validated in human studies.

Is FRRS1L testing available on the NHS?

FRRS1L is not currently included in NHS Genomic Medicine Service gene panels for diagnostic testing. This reflects the lack of established links between FRRS1L variants and specific medical conditions that would warrant routine clinical screening.

How is iron metabolism important for health?

Iron is essential for producing haemoglobin in red blood cells, generating cellular energy in mitochondria, and supporting DNA synthesis. Cells must carefully regulate iron levels, as both deficiency and excess can impair normal function.

Educational content. This page is not medical or genetic advice, is not individually reviewed by a clinician for each reader, and should not replace a consultation with a qualified healthcare professional or genetic counsellor. If you are considering genetic testing or acting on a test result, book a consultation.
Data sources Last updated 17 April 2026. Content compiled from HGNC · MedlinePlus Genetics · ClinGen · Genomics England PanelApp · NHS National Genomic Test Directory · ClinVar · UniProt · AlphaFold .