Motor Neurone Disease

STR: RFC1_CANVAS_ANNGN

Green List (high evidence)

Chromosome: 4
GRCh37 Position: 39350045-39350103
GRCh38 Position: 39348425-39348483
Repeated Sequence: ANNGN
Normal Number of Repeats: < or = 0
Pathogenic Number of Repeats: = or > 400

RFC1 (replication factor C subunit 1, Ensemblv115)
EnsemblGeneIds (GRCh38): ENSG00000035928
EnsemblGeneIds (GRCh37): ENSG00000035928
OMIM: 102579, ClinGen, DECIPHER
RFC1 is in 7 panels

1 review

Bryony Thompson (Royal Melbourne Hospital)

Green List (high evidence)

PMID 38916676 reports three individuals from three families and PMID 38324175 reports three siblings from one family, all with biallelic RFC1 repeat expansions (AAGGG or ACAGG) presenting with adult‑onset motor neuron disease (ALS/PLS or motor neuronopathy) often accompanied by sensory neuropathy, cerebellar ataxia or vestibular deficits.
Created: 22 Sep 2026, 10 p.m. | Last Modified: 22 Sep 2026, 10 p.m.
Panel Version: 2.17
Multiple apparently pathogenic expansions now reported (AGGGC, AAGGC, AGAGG, AAAGG, ACAGG) other than the common AAGGG expansion
Created: 25 Apr 2025, 11:24 a.m.
NM_001204747​.1:c.132+2923_2927AAAAG[X]
Simple tandem repeat (AAAAG)n replaced with (AAGGG)n in intron 2 of RFC1. Loss of function is not the mechanism of disease. Maori population-specific CANVAS configuration (AAAGG)10-25(AAGGG)exp. (AAAGG)n repeat alone is not pathogenic. Mechanism of disease is unknown.
Normal: AAAAG 11 repeats (allele frequency = 0.75); AAAAG 12-200 (allele frequency = 0.13); AAAGG 40-1000 (allele frequency = 0.08)
Pathogenic: AAGGG repeat expansion, most frequently ranging from 400 to more than 2000 repeats (allele frequency = 0.01-0.04)
Sources: Expert list
Created: 29 Aug 2021, 4:30 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome MONDO:0044720

Publications

Details

Name
RFC1_CANVAS_ANNGN
Chromosome
4
GRCh37 Coordinates
39350045-39350103
GRCh38 Coordinates
39348425-39348483
Repeated Sequence
ANNGN
Normal Number of Repeats: < or =
0
Pathogenic Number of Repeats: = or >
400
Mode of Inheritance
BIALLELIC, autosomal or pseudoautosomal
Sources
  • Expert Review Green
  • Expert list
  • Expert list
Phenotypes
  • Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome MIM#614575
Tags
adult-onset
OMIM
102579
ClinGen
RFC1
DECIPHER
RFC1
Clinvar variants
Variants in RFC1
Penetrance
None
Publications

History Filter Activity

Note: This information shows the history of the gene symbol, not the gene entity. Where the gene symbol for a gene has changed, this history may reference a different gene to the entry you are currently viewing.
22 Sep 2026, Gel status: 3

Entity classified by Genomics England curator

Bryony Thompson (Royal Melbourne Hospital)

Str: rfc1_canvas_anngn has been classified as Green List (High Evidence).

22 Sep 2026, Gel status: 3

Set publications

Bryony Thompson (Royal Melbourne Hospital)

Publications for STR: RFC1_CANVAS_ANNGN were set to 30926972; 32851396; 33237689; 31230722; 33237689; 32694621; 33103729; 35355059

22 Sep 2026, Gel status: 3

Created, Added New Source, Added Tag, Set mode of inheritance, Set publications, Set Phenotypes

Bryony Thompson (Royal Melbourne Hospital)

STR: RFC1_CANVAS_ANNGN was added STR: RFC1_CANVAS_ANNGN was added to Motor Neurone Disease. Sources: Expert Review Green,Expert list adult-onset tags were added to STR: RFC1_CANVAS_ANNGN. Mode of inheritance for STR: RFC1_CANVAS_ANNGN was set to BIALLELIC, autosomal or pseudoautosomal Publications for STR: RFC1_CANVAS_ANNGN were set to 30926972; 32851396; 33237689; 31230722; 33237689; 32694621; 33103729; 35355059 Phenotypes for STR: RFC1_CANVAS_ANNGN were set to Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome MIM#614575