HD HTT

Disease ID
HD
Gene ID
HTT
Updated
Apr 2, 2026
v2.17.1
Suggest Edit

Disease

Name
Huntington disease
Inheritance
Autosomal dominant
Description
Huntington disease (HD) is a rare neurodegenerative disorder of the central nervous system characterized by unwanted choreatic movements, behavioral and psychiatric disturbances and dementia1 .
Prevalence
1 10,000
6.5-15/100,0002 . 9.71-17:100,000 (European) vs. 0.1-2/100,000 (African), as many as 1 in 400 have reduced penetrance (0.2-2% for 36-38 CAG) HTT alleles3 . Found across ethnicities/ancestries, with population-dependent prevalence3 .
Age of Onset(Typical)Years1  8535  44
Age of Onset Details
Typical: 35-443 ; Range: 1-854,5 .

Locus

Details
27-35 motifs are unstable/premutations, while 36-39 motifs are associated with reduced penetrance and mild phenotypes6 , and alleles over 40 repeats are typically fully penetrant3 . >60 motifs associated with onset age <20 years3 . Only CAG expansions are considered pathogenic, but interruptions impact pathogenicity (e.g. CAA)7 . Only fathers with premutations are considered at risk of transmitting pathogenic alleles8 . CAG repeats in the non-HD range (>= 21 repeats) may modulate psychiatric disease risk in an age-dependent manner6
Mechanism
GoF/LoF
While the primary pathogenic mechanism is gain of function of the protein product, pathogenesis is complex and multifactorial9 .
Year
199310
Location in Gene
Coding Exon 1
Gene Strand

Alleles

Ref. Motif
CAG
Pathogenic (ref.)
CAG
Pathogenic (gene)
AGC
BenignIntermediatePathogenicUnits6  2627  3536  250

gnomAD

References

Direct supporting references for info on this page.

1
Ontology Lookup Service (OLS)
mondo:0007739
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
4
Expanding the Phenotype of Extremely Early Onset Juvenile Huntington's Disease: A Case Report and Review of Previously Published Cases.
Zöe,Powis, Jonathon,Lutz, Khalida,Liaquat, Jyes A,Querubin, Sat Dev,Batish
American journal of medical genetics. Part A · 2024-10-23
pmid:39441074
5
Huntington's disease: a clinical review.
Raymund A C,Roos
Orphanet journal of rare diseases · 2010-12-20
pmid:21171977
6
Huntingtin CAG repeat size variations below the Huntington's disease threshold: associations with depression, anxiety and basal ganglia structure.
Magdalena,Vater, Nicolas,Rost, Gertrud,Eckstein, Susann,Sauer, Alina,Tontsch, Angelika,Erhardt, Susanne,Lucae, Tanja,Brückl, Thomas,Klopstock, Philipp G,Sämann, Elisabeth B,Binder
European journal of human genetics : EJHG · 2024-11-21
pmid:39572770
7
Comprehensive genetic diagnosis of tandem repeat expansion disorders with programmable targeted nanopore sequencing.
Igor,Stevanovski, Sanjog R,Chintalaphani, Hasindu,Gamaarachchi, James M,Ferguson, Sandy S,Pineda, Carolin K,Scriba, Michel,Tchan, Victor,Fung, Karl,Ng, Andrea,Cortese, Henry,Houlden, Carol,Dobson-Stone, Lauren,Fitzpatrick, Glenda,Halliday, Gianina,Ravenscroft, Mark R,Davis, Nigel G,Laing, Avi,Fellner, Marina,Kennerson, Kishore R,Kumar, Ira W,Deveson
Science advances · 2022-03-04
pmid:35245110
8
Estimating the probability of de novo HD cases from transmissions of expanded penetrant CAG alleles in the Huntington disease gene from male carriers of high normal alleles (27-35 CAG).
Audrey E,Hendricks, Jeanne C,Latourelle, Kathryn L,Lunetta, L Adrienne,Cupples, Vanessa,Wheeler, Marcy E,MacDonald, James F,Gusella, Richard H,Myers
American journal of medical genetics. Part A · 2009-07-01
pmid:19507258
9
Huntington's Disease: Mechanisms of Pathogenesis and Therapeutic Strategies.
Maria,Jimenez-Sanchez, Floriana,Licitra, Benjamin R,Underwood, David C,Rubinsztein
Cold Spring Harbor perspectives in medicine · 2017-07-05
pmid:27940602
10
A novel gene containing a trinucleotide repeat that is expanded and unstable on Huntington's disease chromosomes. The Huntington's Disease Collaborative Research Group.
Cell · 1993-03-26
pmid:8458085

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)

Pyramidal signs in Huntington's disease: An early clinical indicator associated with proximity to disease onset.
Xiao-Yan,Li, Yu-Feng,Bao, Chen-Chang,Hu, Yi,Dong, Zhi-Ying,Wu
Med (New York, N.Y.) · 2026-03-30
pmid:41916314
Inhibition of the NLRP3 Inflammasome With MCC950 Improves Gut Health in Huntington's Disease Mice.
Sujan Kumar,Sarkar, Millicent N,Ekwudo, Da,Lu, Bethany,Masson, Pamudika,Kiridena, Nicholas,van de Garde, Thibault,Renoir, James E,Vince, Veerasikku Gopal,Deepagan, Anthony J,Hannan, Carolina,Gubert
Journal of neurochemistry · 2026-04-01
pmid:41906693
Aberrant expression of the MID1 protein in neurons of Huntington's disease brain.
Adriana,Geraci, Annika,Reisbitzer, Janina,Gerhard, Sybille,Krauß
Frontiers in genetics · 2026-03-11
pmid:41884622
3D-AI mouse behavior analysis system has the capability to detect abnormalities in R6/1 model mice with Huntington's disease during the pre-symptomatic phase.
Shida,Zhou, Xiaoyu,Wang, Yu Tian,Wang
Frontiers in psychiatry · 2026-03-10
pmid:41883719
Huntingtin (HTT) interactome in regulation of DNA repair/remodeling and RNA processing pathways.
Tamara,Ratovitski, Chloe D,Holland, Robert N,O'Meally, Alexey V,Shevelkin, Siddhi V,Kamath, Tianze,Shi, Matthew J,Rodriguez, Robert N,Cole, Mali,Jiang, Christopher A,Ross
Life science alliance · 2026-03-18
pmid:41850723
Self-inactivating AAV-CRISPR at different ages enables sustained amelioration of Huntington's disease deficits in BAC226Q mice.
Yuanyi,Dai, Zuliayeti,Abudujielili, Yunyi,Ding, Wanping,Huang, Jianhang,Yin, Liqiong,Ou, Jiazhi,Hu, Sushuang,Zheng, Chenjian,Li
Science advances · 2026-03-18
pmid:41849610
Lowering the
Aikaterini Smaragdi,Papadopoulou, Julia,Alterman, Christian,Landles, Edward J,Smith, Faith,Conroy, Jemima,Phillips, Maria,Canibano-Pico, Iulia M,Nita, Georgina F,Osborne, Arzo,Iqbal, Sarah G,Aldous, Marie K,Bondulich, Casandra,Gomez-Paredes, Kirupa,Sathasivam, Daniel,O'Reilly, Dimas,Echeverria, Konstantin,Bobkov, Jonathan R,Greene, Neil,Aronin, Anastasia,Khvorova, Gillian P,Bates
Science translational medicine · 2026-03-18
pmid:41849583
Discovery and Optimization of Thienopyrazine RNA-Splicing Modulators for the Treatment of Huntington's Disease.
Chaofan,Xu, Neeta,Abraham, Nupur,Bansal, Philippe N,Bolduc, Patrick,Cullen, Thomas M,Carlile, Yirui,Chen, Colin K,Choi, Rachelle,Driscoll, Eric,Stefan, Christina M,Gallo, Zhen,Gao, Catherine L,Guardado, Guilherme,Guimaraes, James,Harvey, Sarah,Huff, Dann,Huh, Jessica,Hurt, Melissa M,Kemp, Kwang Soo,Lee, Joon,Lee, Mukesh,Lulla, Soumya,Negi, Marta,Nevalainen, Emily A,Peterson, Thomas J,Purgett, Joseph C,Santoro, Daniel R,Smith, Andreas,Weihofen, Zain,Yousaf, Magnus,Pfaffenbach
Journal of medicinal chemistry · 2026-03-17
pmid:41841355
High-affinity, structure-validated and selective macrocyclic peptide tools for chemical biology studies of Huntingtin.
Rebeka,Fanti, Esther,Wolf, Tatsuya,Ikenoue, Justin C,Deme, Swati,Balakrishnan, Brandon A,Keith, Matthew G,Alteen, Renu,Chandrasekaran, Manisha,Yadav, Ritika,Bhajiawala, Suzanne,Ackloo, Jia,Feng, Mahmoud A,Pouladi, Aled M,Edwards, Derek J,Wilson, Susan M,Lea, Hiroaki,Suga, Rachel J,Harding
Proceedings of the National Academy of Sciences of the United States of America · 2026-03-16
pmid:41838909