SCA17 TBP
Definitive Som. Inst.Anticip.Pat. Exp.Len. → OnsetLen. → Pen.Len. → Pheno.Mot. → Inst.
Disease ID
SCA17
Gene ID
TBP
Updated
May 15, 2026
v2.20.0
Clinical Links
GARD
10469
GeneReviews
NBK1438
MalaCard
SPN296
MedGen
337637
Mondo
0011781
OMIM
607136
Orphanet
98759
DECIPHER
TBP
Bioinformatical Links
gnomAD
TBP
STRipy
TBP
TR-Atlas
TR72502
WebSTR hg38
83566
TR Explorer
chr6:170561907-170562017
Suggest Edit

Disease
SCA
Name
Spinocerebellar ataxia type 17
Inheritance
Autosomal dominant
Description
A rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I). It is characterized by a variable clinical picture which can include dementia, psychiatric disorders, parkinsonism, dystonia, chorea, spasticity, and epilepsy1 .
Prevalence
0.2 100,000
Unknown (global), <100 families, 0.47:1,000,000 (Japanese), 0.16/100,000 (England)2,3 : 0.2/100,000. Found across ethnicities/ancestries, with population-dependent prevalence2 .
Age of Onset(Typical)Years3  6219  48
Age of Onset Details
Typical: 19-48; Range: 3-62, has second variant to delay onset .

Locus
hg19
chr6:170870994-170871105
hg38
chr6:170561906-170562017
t2t
chr6:171935458-171935569
Details
Benign range is 25-40 repeats, pathogenic range is 49+ repeats (largest to date 66 motifs, with mild correlation between size and age of onset), and intermediate alleles (41-48 repeats) are associated with reduced penetrance and potentially milder phenotypes2 . Huntington's disease like phenotype4 . CAA CAG CAA interruption is seen in all alleles stably transmitted across generations2,5 .
Mechanism
LoF/GoF
Polyglutamine expansion leading to transcriptional dysregulation6 .
Year
19997
Location in Gene
Coding Exon 3
Gene Strand

Alleles
Ref. Motif
CAG
Pathogenic (ref.)
CAG
Pathogenic (gene)
AGC
Interruption (ref.)
CAA
Interruption (gene)
AAC
BenignIntermediatePathogenicUnits25  4041  4849  66

gnomAD

Pathogenic genotype frequency data is not displayed for this locus because a substantial number of large alleles failed manual review by the gnomAD team.

References

Direct supporting references for info on this page.

omim:607136,@pmid:35053321,@genereviews:NBK1438,@pmid:12805114,@genereviews:NBK1438
pmid:35245110,@genereviews:NBK1438,@pmid:29100084,@pmid:10484774,@mondo:0011781

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)

Detection of short tandem repeat expansions on a targeted neurological gene panel using STRipy improves the diagnostic rate for ataxias.
Carolin K,Scriba, Chiara,Folland, Michael,Black, Jessica,Baker, Daniel,Abromeit, Samantha,Saw, Mei-Ting,Chiew, Rebecca,Gooding, Nigel G,Laing, Mark R,Davis, Gianina,Ravenscroft
Brain communications · 2026-03-16
pmid:42038259
Childhood-Onset Huntington's Disease-Like Presentation of SCA17 with Intermediate Repeats, A Case Report.
Meaghan,Berns, Kelsey,Jensen, Laura,Speltz, Leonardo Brito,Almeida
Cerebellum (London, England) · 2026-03-17
pmid:41843312
Short tandem repeat expansions in patients with neurodegenerative dementia.
Yuan,Zhu, Xuewen,Xiao, Yiliang,Liu, Zheng,Wang, Tengfei,Luo, Tianyan,Xu, Qijie,Yang, Xiaoli,Hao, Cong,Zhang, Sizhe,Zhang, Shilin,Luo, Yafang,Zhou, Xinxin,Liao, Yun,Tian, Ling,Weng, Liangjuan,Fang, Beisha,Tang, Bin,Jiao, Jinchen,Li, Lu,Shen
EBioMedicine · 2026-02-26
pmid:41762523
Non-Huntington's disease chorea: an expanding universe with acquired causes.
Francisco,Cardoso, Débora,Maia, Ricardo,Maciel, Jonathan,Carr, Taku,Hatano, Alexandra,Durr, Werner,Poewe
Brain : a journal of neurology · 2026-01-30
pmid:41612618
Repeat Variants, Biomarkers, and Molecular Signatures in Parkinson's Disease:
Jose Miguel,Laffita-Mesa, Martin,Paucar, Per,Svenningsson
International journal of molecular sciences · 2025-09-20
pmid:41009775
Diagnostic yield and limitations of whole-genome sequencing for hereditary cerebellar ataxia.
Wai Yan,Yau, Roisin,Sullivan, Emer,O'Connor, David,Pellerin, Michael H,Parkinson, Paola,Giunti, Marie-Josée,Dicaire, Matt C,Danzi, Stephan,Züchner, Bernard,Brais, Nicholas W,Wood, Henry,Houlden, Jana,Vandrovcova
Brain communications · 2025-05-17
pmid:40488180
Isolated Generalized Chorea in a Patient with Small-Expanded Allele Spinocerebellar Ataxia 17.
Giulia,Paparella, Martina,De Riggi, Simone,Aloisio, Adriana,Martini, Luca,Angelini, Daniele,Birreci, Davide,Costa, Antonio,Cannavacciuolo, Anna Maria,Griguoli, Stefano,Gambardella, Matteo,Bologna
Cerebellum (London, England) · 2025-06-06
pmid:40478462
TBP Repeat Expansion Analysis in Patients Carrying Heterozygous STUB1 Variants.
Jonathan,De Winter, Liedewei,Van de Vondel, Kristof,Van Schil, Tine,Deconinck, Katrien,Storm, Karine,Geens, Charlotte,Sommeling, David,Crosiers, Emke,Marechal, Willem,De Ridder, Peter,De Jonghe, Jonathan,Baets
Movement disorders : official journal of the Movement Disorder Society · 2025-02-14
pmid:39950762
ATXN10 Gene Expansions in Mexican Patients with Ataxia Without Epilepsy.
Aurelio,Jara-Prado, Eukeni,Arias-Capistran, Jorge,Guerrero-Camacho, Adriana,Ochoa-Morales, Marie Catherine,Boll, David,Dávila-Ortíz de Montellano, Astrid,Rasmussen, Tetsuo,Ashizawa, Juan,Fernandez-Ruiz, Petra,Yescas-Gómez, Miguel Ángel,Ramírez-García
Cerebellum (London, England) · 2025-01-16
pmid:39820777