SCA2 ATXN2

Disease ID
SCA2
Gene ID
ATXN2
Updated
Apr 2, 2026
v2.17.1
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Disease

SCA
Name
Spinocerebellar ataxia type 2
Description
A subtype of type I autosomal dominant cerebellar ataxia (ADCA type I) characterized by truncal ataxia, dysarthria, slowed saccades and less commonly ophthalmoparesis and chorea1 .
Prevalence
1.5 100,000
1-2/100,000 (population-dependent)2 . Cases have been found across ethnicities/ancestries, with population-dependent prevalence3 .
Age of Onset(Typical)Years2  8630  39
Age of Onset Details
Typical: 30-393 ; Range: 2-864 .

Locus

Details
Full penetrance of single alleles occurs at ~35 repeats3,5 and pathogenic expansions have been documented as large as 500 repeats6 . 33-34 length repeats are associated with reduced penetrance and later onset (age >50 years)3 . Homozygous 31 repeat alleles may lead to recessive disease7 , while a single 29-32 repeat is associated with increased ALS risk3,8,9 . There is some evidence that all CAG-repeat expansions in ATXN2 may be a risk factor for ALS, regardless of length and interruptions10 . Interruptions observed include CAA, CGG, CGC, which appear to stabilize the allele in transmission3 .
Mechanism
GoF/LoF
Polyglutamine cytoplasmic aggregates leading to cellular apoptosis; RAN translation implicated3 .
Year
199611
Location in Gene
Coding Exon 1
Gene Strand

Alleles

Ref. Motif
CTG
Pathogenic (ref.)
CTG
Pathogenic (gene)
AGC
BenignIntermediatePathogenicUnits14  2829  3435  500

gnomAD

References

Direct supporting references for info on this page.

1
Ontology Lookup Service (OLS)
mondo:0008458
2
Profiling of Short-Tandem-Repeat Disease Alleles in 12,632 Human Whole Genomes.
Haibao,Tang, Ewen F,Kirkness, Christoph,Lippert, William H,Biggs, Martin,Fabani, Ernesto,Guzman, Smriti,Ramakrishnan, Victor,Lavrenko, Boyko,Kakaradov, Claire,Hou, Barry,Hicks, David,Heckerman, Franz J,Och, C Thomas,Caskey, J Craig,Venter, Amalio,Telenti
American journal of human genetics · 2017-11-02
pmid:29100084
5
The Frequency of Intermediate Alleles in Patients with Cerebellar Phenotypes.
Elena,Capacci, Silvia,Bagnoli, Giulia,Giacomucci, Costanza Maria,Rapillo, Alessandra,Govoni, Valentina,Bessi, Cristina,Polito, Irene,Giotti, Alice,Brogi, Elisabetta,Pelo, Sandro,Sorbi, Benedetta,Nacmias, Camilla,Ferrari
Cerebellum (London, England) · 2023-10-31
pmid:37906407
6
Childhood-onset ataxia: testing for large CAG-repeats in SCA2 and SCA7.
Rong,Mao, Arthur S,Aylsworth, Nicholas,Potter, William G,Wilson, Galen,Breningstall, Myra J,Wick, Dusica,Babovic-Vuksanovic, Martha,Nance, Marc C,Patterson, Christopher M,Gomez, Karen,Snow
American journal of medical genetics · 2002-07-15
pmid:12116207
7
Homozygous 31 trinucleotide repeats in the SCA2 allele are pathogenic for cerebellar ataxia.
Maya,Tojima, Gaku,Murakami, Rie,Hikawa, Hodaka,Yamakado, Hirofumi,Yamashita, Ryosuke,Takahashi, Masaru,Matsui
Neurology. Genetics · 2018-10-16
pmid:30533529
8
Amyotrophic lateral sclerosis risk for spinocerebellar ataxia type 2 ATXN2 CAG repeat alleles: a meta-analysis.
Annalese G,Neuenschwander, Khanh K,Thai, Karla P,Figueroa, Stefan M,Pulst
JAMA neurology · 2014-12-01
pmid:25285812
9
Gijs H P,Tazelaar, Steven,Boeynaems, Mathias,De Decker, Joke J F A,van Vugt, Lindy,Kool, H Stephan,Goedee, Russell L,McLaughlin, William,Sproviero, Alfredo,Iacoangeli, Matthieu,Moisse, Maarten,Jacquemyn, Dirk,Daelemans, Annelot M,Dekker, Rick A,van der Spek, Henk-Jan,Westeneng, Kevin P,Kenna, Abdelilah,Assialioui, Nica,Da Silva, Mónica,Povedano, Jesus S Mora,Pardina, Orla,Hardiman, François,Salachas, Stéphanie,Millecamps, Patrick,Vourc'h, Philippe,Corcia, Philippe,Couratier, Karen E,Morrison, Pamela J,Shaw, Christopher E,Shaw, R Jeroen,Pasterkamp, John E,Landers, Ludo,Van Den Bosch, Wim,Robberecht, Ammar,Al-Chalabi, Leonard H,van den Berg, Philip,Van Damme, Jan H,Veldink, Michael A,van Es
Brain communications · 2020-05-19
pmid:32954321
11
Identification of the spinocerebellar ataxia type 2 gene using a direct identification of repeat expansion and cloning technique, DIRECT.
K,Sanpei, H,Takano, S,Igarashi, T,Sato, M,Oyake, H,Sasaki, A,Wakisaka, K,Tashiro, Y,Ishida, T,Ikeuchi, R,Koide, M,Saito, A,Sato, T,Tanaka, S,Hanyu, Y,Takiyama, M,Nishizawa, N,Shimizu, Y,Nomura, M,Segawa, K,Iwabuchi, I,Eguchi, H,Tanaka, H,Takahashi, S,Tsuji
Nature genetics · 1996-11-01
pmid:8896556

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)

The Role of D/H Isotope Exchange in Stabilizing Trinucleotide Repeat Expansions in the CAG Tract of the ATXN2 Gene.
A A,Dorohova, I M,Chernukha, L V,Fedulova, J L,Hernandez-Caceres, M I,Drobotenko, S S,Dzhimak
Doklady. Biochemistry and biophysics · 2026-03-30
pmid:41912844
Monitoring the Progression of Pre-Ataxic Gait in SCA2 with Inertial Sensors Over Four Years.
Luis,Velázquez-Pérez, Roberto,Rodríguez-Labrada, Yasmany,Gonzalez-Garcés, Frank J,Carrillo-Rodes, Julio C,Rodríguez-Díaz, Yaimeé,Vázquez-Mojena, Ulf,Ziemann, Georg,Auburger, Fay,Horak, Christopher,Gomez
Cerebellum (London, England) · 2026-03-25
pmid:41876820
Metformin improves RAN protein pathology, alternative splicing, and behavioral phenotypes in SCA8 mice.
Lisa El,Romano, Setsuki,Tsukagoshi, Emily E,Davey-Osuch, Ramadan,Ajredini, Kamat,Manasi, Tala Vr,Ortiz, Eduardo,Rijos, Nathan J,Bourgon, S Elaine,Ames, Timothy J,Garrett, John D,Cleary, Eric T,Wang, Laura Pw,Ranum
Life science alliance · 2026-03-02
pmid:41771688
Bi-allelic intermediate ATXN2 repeat expansions are associated with slow progressing, leg-onset familial ALS.
Koen Cedric,Demaegd, Wouter,Koole, Joke Jfa,van Vugt, Jan Willem,Dankbaar, Jeroen,Hendrikse, A,Nazlı Başak, Mamede,de Carvalho, Philippe,Corcia, Philippe,Codron, Emilien,Bernard, Claire,Guissart, Philippe,Couratier, Mónica,Povedano Panades, Pieter A,van Doorn, Bart P,Warrenburg, Johnathan,Cooper-Knock, R Jeroen,Pasterkamp, Wouter,van Rheenen, Philip,van Damme, Leonard H,van den Berg, Jan Herman,Veldink, Michael A,van Es
BMJ neurology open · 2026-02-18
pmid:41728197
Mitochondrial DNA Haplogroups and Age at Onset of Spinocerebellar Ataxia Type 2: A Study in Indian Patients.
Akhilesh Kumar,Sonakar, Chhavi,Sharma, Shahrumi,Reza, Shivam,Pandey, M V Padma,Srivastava, Achal K,Srivastava, Mohammed,Faruq
Annals of Indian Academy of Neurology · 2026-02-16
pmid:41693683
Preimplantation Genetic Testing of Spinocerebellar Ataxia Type 2-Robust Tools for Direct and Indirect Detection of the ATXN2 CAG Repeat Expansion.
Nur,Asherah, Mulias,Lian, Arnold S,Tan, Riho,Taguchi, Pengyian,Chua, Shuling,Liu, Caroline G,Lee, Samuel S,Chong
International journal of molecular sciences · 2026-02-04
pmid:41683965
Expanding the Genetic Landscape of
Jacob,Saucier, Mohammad,Al-Qadi, Eric Pierre,Allain, Philippe-Pierre,Robichaud, Ludivine,Chamard-Witkowski, Mario,Alvarez, Anne-Marie,Dion-Côté, Luc,Richard, Nicolas,Crapoulet, Mouna,Ben Amor
Neurology. Genetics · 2026-02-02
pmid:41630926
Valosin-Containing Protein as a therapeutic target in CAG repeat-driven Spinocerebellar ataxias: Integrative transcriptomic and computational insights.
Surbhi,Singh, Deepika,Joshi, Janki,Makani, Suchitra,Singh, Janhavi,Yadav, Shraddha,Chaurasiya, Chandmayee,Mohanty, Anand,Kumar, Royana,Singh
Computational biology and chemistry · 2025-12-11
pmid:41435767
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