FTDALS1 C9orf72

Disease ID
FTDALS1
Gene ID
C9orf72
Updated
Jan 23, 2026
v2.15.0
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Disease

Name
Frontotemporal dementia (FTD) and/or amyotrophic lateral sclerosis (ALS)
Inheritance
Autosomal dominant
Description
Pure frontotemporal dementia, pure amyotrophic lateral sclerosis or combination of the two1 . Nominal associations with risk of Parkinson's have also been reported2 .
Prevalence
The expansion of a hexanucleotide repeat GGGGCC in C9orf72 is the most common known cause of ALS accounting for ~ 40% familial cases and ~ 7% sporadic cases in the European population; overall ALS incidence is 1-2/100,000 person-years, point prevalence is 3-5/100,000 (Europe/US); lifetime risk is 1 in 3003 . Related individuals to patients with C9orf72-ALS appear at an increased risk of disease regardless of carrier status4,5 . C9orf72-FTD is estimated to be 0.04-134:100,0006 , and by our estimates 0.65-1.56/100,000 for C9orf72-ALS. The expansion has been found across ethnicities/ancestries, with population-dependent prevalence, highest in those with northern European ancestry6 .
Age of Onset(Typical)Years20  9150  64
Age of Onset Details
Typical: 50-64; Range: 20-916 .

Locus

Details
FTD and ALS form a clinical spectrum7,8 . The clinical ranges of the C9orf72 locus remain ambiguous9 : most healthy controls have alleles up to 24 repeats10 yet 24-30 repeats are associated with ALS3 and while 60 repeats is frequently used as a threshold for uncertain alleles, the exact threshold of pathogenicity remains unclear6,11 . Repeats of 80 motifs and lower appear to have delayed onset for any phenotype10 . >250 repeats are associated with a full FTD/ALS disease state12 , but pathogenic alleles can range from 30 to more than 4000 repeats11,13 . Penetrance appears to also be age-dependent, with environmental factors and specific phenotypes associated with sex and age at onset14 . Methylation appears to increase with expansion length and age13 .
Mechanism
Ambiguous
The HRE forms DNA and RNA G-quadruplexes with distinct structures and promotes RNA/DNA hybrids (R-loops). The structural polymorphism causes a repeat length-dependent accumulation of transcripts aborted in the HRE region15 . Addiitonal mechanisms theorized include protein loss of function and RNA gain of function16 . Multiple cell types in the prefrontal cortex, including oligodendrocytes, microglia, astrocytes, and neurons, appear impacted during pathogenesis17 .
Year
201118
Location in Gene
Intron 1 or 5' UTR depending on transcript
Gene Strand

Alleles

Ref. Motif
GGCCCC
Pathogenic (ref.)
GGCCCC
Pathogenic (gene)
CCGGGG
BenignIntermediatePathogenicUnits2  2324  60251  4,088

gnomAD

References

Direct supporting references for info on this page.

1
Repeat expansion disorders.
Zhongbo,Chen, Huw R,Morris, James,Polke, Nicholas W,Wood, Sonia,Gandhi, Mina,Ryten, Henry,Houlden, Arianna,Tucci
Practical neurology · 2025-05-15
pmid:39349043
2
Association of Non-Coding Repeat Expansions with Parkinson's Disease Risk: Evidence from a UK Biobank-Based Whole-Genome Sequencing Study.
Zhen,Hu, Qin-Qin,Yan, Jing-Jin,Wan, Yu,Fan, Jun,Liu
Movement disorders : official journal of the Movement Disorder Society · 2025-10-11
pmid:41074692
3
C9orf72 intermediate expansions of 24-30 repeats are associated with ALS.
Alfredo,Iacoangeli, Ahmad,Al Khleifat, Ashley R,Jones, William,Sproviero, Aleksey,Shatunov, Sarah,Opie-Martin, Karen E,Morrison, Pamela J,Shaw, Christopher E,Shaw, Isabella,Fogh, Richard J,Dobson, Stephen J,Newhouse, Ammar,Al-Chalabi
Acta neuropathologica communications · 2019-07-17
pmid:31315673
4
Marie,Ryan, Mark A,Doherty, Ahmad,Al Khleifat, Emmet,Costello, Jennifer C,Hengeveld, Mark,Heverin, Ammar,Al-Chalabi, Russell L,Mclaughlin, Orla,Hardiman
Neurology. Genetics · 2023-12-22
pmid:38149039
5
Personalised penetrance estimation for C9orf72-related amyotrophic lateral sclerosis and frontotemporal dementia.
Andrew G L,Douglas, Alexander G,Thompson, Martin R,Turner, Kevin,Talbot
BMJ neurology open · 2024-09-18
pmid:39315390
6
C9orf72 Frontotemporal Dementia and/or Amyotrophic Lateral Sclerosis
Helena,Gossye, Sebastiaan,Engelborghs, Christine,Van Broeckhoven, Julie,Zee
GeneReviews® · 1993-01-01
genereviews:NBK268647
7
Genome-wide structural variant analysis identifies risk loci for non-Alzheimer's dementias.
Karri,Kaivola, Ruth,Chia, Jinhui,Ding, Memoona,Rasheed, Masashi,Fujita, Vilas,Menon, Ronald L,Walton, Ryan L,Collins, Kimberley,Billingsley, Harrison,Brand, Michael,Talkowski, Xuefang,Zhao, Ramita,Dewan, Ali,Stark, Anindita,Ray, Sultana,Solaiman, Pilar,Alvarez Jerez, Laksh,Malik, Ted M,Dawson, Liana S,Rosenthal, Marilyn S,Albert, Olga,Pletnikova, Juan C,Troncoso, Mario,Masellis, Julia,Keith, Sandra E,Black, Luigi,Ferrucci, Susan M,Resnick, Toshiko,Tanaka, Eric,Topol, Ali,Torkamani, Pentti,Tienari, Tatiana M,Foroud, Bernardino,Ghetti, John E,Landers, Mina,Ryten, Huw R,Morris, John A,Hardy, Letizia,Mazzini, Sandra,D'Alfonso, Cristina,Moglia, Andrea,Calvo, Geidy E,Serrano, Thomas G,Beach, Tanis,Ferman, Neill R,Graff-Radford, Bradley F,Boeve, Zbigniew K,Wszolek, Dennis W,Dickson, Adriano,Chiò, David A,Bennett, Philip L,De Jager, Owen A,Ross, Clifton L,Dalgard, J Raphael,Gibbs, Bryan J,Traynor, Sonja W,Scholz
Cell genomics · 2023-05-04
pmid:37388914
8
Frequency of the C9orf72 hexanucleotide repeat expansion in patients with amyotrophic lateral sclerosis and frontotemporal dementia: a cross-sectional study.
Elisa,Majounie, Alan E,Renton, Kin,Mok, Elise G P,Dopper, Adrian,Waite, Sara,Rollinson, Adriano,Chiò, Gabriella,Restagno, Nayia,Nicolaou, Javier,Simon-Sanchez, John C,van Swieten, Yevgeniya,Abramzon, Janel O,Johnson, Michael,Sendtner, Roger,Pamphlett, Richard W,Orrell, Simon,Mead, Katie C,Sidle, Henry,Houlden, Jonathan D,Rohrer, Karen E,Morrison, Hardev,Pall, Kevin,Talbot, Olaf,Ansorge, Dena G,Hernandez, Sampath,Arepalli, Mario,Sabatelli, Gabriele,Mora, Massimo,Corbo, Fabio,Giannini, Andrea,Calvo, Elisabet,Englund, Giuseppe,Borghero, Gian Luca,Floris, Anne M,Remes, Hannu,Laaksovirta, Leo,McCluskey, John Q,Trojanowski, Vivianna M,Van Deerlin, Gerard D,Schellenberg, Michael A,Nalls, Vivian E,Drory, Chin-Song,Lu, Tu-Hsueh,Yeh, Hiroyuki,Ishiura, Yuji,Takahashi, Shoji,Tsuji, Isabelle,Le Ber, Alexis,Brice, Carsten,Drepper, Nigel,Williams, Janine,Kirby, Pamela,Shaw, John,Hardy, Pentti J,Tienari, Peter,Heutink, Huw R,Morris, Stuart,Pickering-Brown, Bryan J,Traynor
The Lancet. Neurology · 2012-03-09
pmid:22406228
9
STRipy - STRs database (C9ORF72 locus)
stripy:C9ORF72
10
Relationship between C9orf72 repeat size and clinical phenotype.
Sara,Van Mossevelde, Julie,van der Zee, Marc,Cruts, Christine,Van Broeckhoven
Current opinion in genetics & development · 2017-03-17
pmid:28319737
11
Analysis of normal
Silvia,Peverelli, Alberto,Brusati, Valeria,Casiraghi, Marta Nice,Sorce, Sabrina,Invernizzi, Serena,Santangelo, Claudia,Morelli, Federico,Verde, Vincenzo,Silani, Nicola,Ticozzi, Antonia,Ratti
Amyotrophic lateral sclerosis & frontotemporal degeneration · 2024-01-23
pmid:38099605
12
C9orf72 and triplet repeat disorder RNAs: G-quadruplex formation, binding to PRC2 and implications for disease mechanisms.
Xueyin,Wang, Karen J,Goodrich, Erin G,Conlon, Jianchao,Gao, Annette H,Erbse, James L,Manley, Thomas R,Cech
RNA (New York, N.Y.) · 2019-05-02
pmid:31048495
13
Targeted long-read sequencing to quantify methylation of the C9orf72 repeat expansion.
Evan,Udine, NiCole A,Finch, Mariely,DeJesus-Hernandez, Jazmyne L,Jackson, Matthew C,Baker, Siva Arumugam,Saravanaperumal, Eric,Wieben, Mark T W,Ebbert, Jaimin,Shah, Leonard,Petrucelli, Rosa,Rademakers, Björn,Oskarsson, Marka,van Blitterswijk
Molecular neurodegeneration · 2024-12-21
pmid:39709476
14
Age-related penetrance of the C9orf72 repeat expansion.
Natalie A,Murphy, Karissa C,Arthur, Pentti J,Tienari, Henry,Houlden, Adriano,Chiò, Bryan J,Traynor
Scientific reports · 2017-05-18
pmid:28522837
16
Roadmap for C9ORF72 in Frontotemporal Dementia and Amyotrophic Lateral Sclerosis: Report on the C9ORF72 FTD/ALS Summit.
Rita,Sattler, Bryan J,Traynor, Janice,Robertson, Ludo,Van Den Bosch, Sami J,Barmada, Clive N,Svendsen, Matthew D,Disney, Tania F,Gendron, Philip C,Wong, Martin R,Turner, Adam,Boxer, Suma,Babu, Michael,Benatar, Michael,Kurnellas, Jonathan D,Rohrer, Christopher J,Donnelly, Lynette M,Bustos, Kendall,Van Keuren-Jensen, Penny A,Dacks, Marwan N,Sabbagh
Neurology and therapy · 2023-10-17
pmid:37847372
17
pTDP-43 levels correlate with cell type-specific molecular alterations in the prefrontal cortex of
Hsiao-Lin V,Wang, Jian-Feng,Xiang, Chenyang,Yuan, Austin M,Veire, Tania F,Gendron, Melissa E,Murray, Malú G,Tansey, Jian,Hu, Marla,Gearing, Jonathan D,Glass, Peng,Jin, Victor G,Corces, Zachary T,McEachin
Proceedings of the National Academy of Sciences of the United States of America · 2025-02-25
pmid:39999167
18
Expanded GGGGCC hexanucleotide repeat in noncoding region of C9ORF72 causes chromosome 9p-linked FTD and ALS.
Mariely,DeJesus-Hernandez, Ian R,Mackenzie, Bradley F,Boeve, Adam L,Boxer, Matt,Baker, Nicola J,Rutherford, Alexandra M,Nicholson, NiCole A,Finch, Heather,Flynn, Jennifer,Adamson, Naomi,Kouri, Aleksandra,Wojtas, Pheth,Sengdy, Ging-Yuek R,Hsiung, Anna,Karydas, William W,Seeley, Keith A,Josephs, Giovanni,Coppola, Daniel H,Geschwind, Zbigniew K,Wszolek, Howard,Feldman, David S,Knopman, Ronald C,Petersen, Bruce L,Miller, Dennis W,Dickson, Kevin B,Boylan, Neill R,Graff-Radford, Rosa,Rademakers
Neuron · 2011-09-21
pmid:21944778

Additional Literature

Additional literature related to this locus.

Raw PubMed search results
(All PubMed results returned by searching for this gene, tandem repeats, and disease, in medline format)

Preclinical Evaluation of the Assembly Modulator PAV-615 in a Mouse Model of
Jingfen,Su, Jorge,Alaiz Noya, Anuradha F,Lingappa, Dennis,Solas, Jimei,Tong, Lillian,Daughrity, Monica,Castanedes-Casey, Aishe,Kurti, Dennis W,Dickson, Vishwanath R,Lingappa, Leonard,Petrucelli, Yongjie,Zhang
Cells · 2025-12-17
pmid:41440030
Loss of Y chromosome and its implications in male amyotrophic lateral sclerosis: insights from the UK Biobank.
Wei-Ming,Su, Qing-Qing,Duan, Sheng-Yi,He, Ru-Yin,Liu, Xiang-Jin,Wen, Nan,Zhang, Ting,Chen, Bei,Cao, Yong-Ping,Chen
BMC medicine · 2025-12-24
pmid:41437053
The role of disease-associated short tandem repeats in amyotrophic lateral sclerosis.
Joke J F A,van Vugt, Ramona A J,Zwamborn, Egor,Dolzhenko, Michael A,Eberle, Ben,Weisburd, Erwin,Bekema, Maarten,Kooyman, Bi-Nan,Wang, Erik-Jan,Kamsteeg, Monique,Losekoot, Frank,Baas, Camilla,Novy, Helle,Høyer, Ruben P A,van Eijk, Michael A,van Es, Wouter,van Rheenen, Ammar,Al-Chalabi, Leonard H,van den Berg, Jan H,Veldink
Brain communications · 2025-12-09
pmid:41426430
Support vector machine classification of
Chunmeng,Tang, Juliette,Foucher, Linn,Öijerstedt, Fouke,Ombelet, Caroline,Ingre, Philip,Van Damme, Koen,Van Laere, Joke,De Vocht, Michel,Koole
European journal of nuclear medicine and molecular imaging · 2025-12-22
pmid:41423553
Thermally activated irreversible homogenization of G-quadruplexes in an ALS/FTD-associated gene.
Daniel,Ross, Olivia,Lewis, Olivia,McLean, Sundeep,Bhanot, Shane,Donahue, Rachael,Baker, Randi,Dias, David,Eagerton, Vaibhav,Mohanty, Bidyut K,Mohanty
bioRxiv : the preprint server for biology · 2025-11-24
pmid:41394713
The molecular mechanism of uptake and cell-to-cell transmission of arginine-containing dipeptide repeat proteins.
Alexandra B,Sutter, Benito F,Buksh, Jelena,Mojsilovic-Petrovic, Casey,Dalton, Nicholas A,Till, Danielle C,Morgan, David W C,MacMillan, Robert G,Kalb
bioRxiv : the preprint server for biology · 2025-11-28
pmid:41394638
Brain metabolic connectivity in ALS due to C9ORF72 hexanucleotide expansion: a [
Antonio,Canosa, Stefano,Callegaro, Umberto,Manera, Rosario,Vasta, Sara,Cabras, Francesca,Di Pede, Filippo,De Mattei, Francesca,Palumbo, Barbara,Iazzolino, Anastasia,Dei Giudici, Enrico,Matteoni, Grazia,Zocco, Emilio,Minerva, Alessandra,Maccabeo, Giorgio,Pellegrino, Daniela,Pascariu, Maurizio,Grassano, Pietro,Piombino, Marcella,Testa, Giulia,Polverari, Giuseppe,Fuda, Ilaria,Merulla, Federico,Casale, Salvatore,Gallone, Cristina,Moglia, Andrea,Calvo, Marco,Pagani, Adriano,Chiò
European journal of nuclear medicine and molecular imaging · 2025-12-11
pmid:41379346
Quantifying multimodal longitudinal brain changes in presymptomatic C9orf72 disease.
Dario,Saracino, Lorenzo,Cipriano, Marion,Houot, Giorgia,Querin, Daisy,Rinaldi, Armelle,Rametti-Lacroux, David,Wallon, Emmanuel,Gerardin, Philippe,Couratier, Marie-Paule,Boncoeur, Thibaud,Lebouvier, Olivier,Colliot, Pierre-François,Pradat, Raffaella,Migliaccio, Isabelle,Le Ber
Alzheimer's & dementia : the journal of the Alzheimer's Association · 2025-12-01
pmid:41366786
Novel and rare variants in amyotrophic lateral sclerosis genes identified in Malaysian patients.
Nurul Angelyn,Zulhairy-Liong, Suzanna,Edgar, Melina,Ellis, Danqing,Zhu, Kaitao,Lai, David Paul,Capelle, Sakinah,Sabirin, Eu Way,Pek, Prasana,Nair, Chui Munn,Ang, Marina L,Kennerson, Nortina,Shahrizaila, Azlina,Ahmad-Annuar
Amyotrophic lateral sclerosis & frontotemporal degeneration · 2025-12-08
pmid:41359433