{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T17:29:10Z","timestamp":1791912550333,"version":"4.3.4"},"reference-count":23,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2020,8,20]],"date-time":"2020-08-20T00:00:00Z","timestamp":1597881600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000065","name":"National Institute of Neurological Disorders and Stroke","doi-asserted-by":"publisher","award":["R01NS055903"],"award-info":[{"award-number":["R01NS055903"]}],"id":[{"id":"10.13039\/100000065","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>There is a known negative association between cytosine\u2013adenine\u2013guanine (CAG) repeat length and the age of motor onset (AMO) in adult-onset Huntington\u2019s Disease (AOHD). This relationship is less clear in patients with juvenile-onset Huntington\u2019s disease (JOHD), however, given the rarity of this patient population. The aim of this study was to investigate this relationship amongst a relatively large group of patients with JOHD using data from the Kids-JOHD study. Additionally, we analyzed data from the Enroll-HD platform and the Predict-HD study to compare the relationship between CAG repeat length and AMO amongst patients with AOHD to that amongst patients with JOHD using linear regression models. In line with previous reports, the variance in AMO that was predicted by CAG repeat length was 59% (p &lt; 0.0001) in the Predict-HD study and 57% from the Enroll-HD platform (p &lt; 0.0001). However, CAG repeat length predicted 84% of the variance in AMO amongst participants from the Kids-JOHD study (p &lt; 0.0001). These results indicate that there may be a stronger relationship between CAG repeat length and AMO in patients with JOHD as compared to patients with AOHD. These results provide additional information that may help to model disease progression of JOHD, which is beneficial for the planning and implementation of future clinical trials.<\/jats:p>","DOI":"10.3390\/brainsci10090575","type":"journal-article","created":{"date-parts":[[2020,8,20]],"date-time":"2020-08-20T09:35:31Z","timestamp":1597916131000},"page":"575","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["The Association between CAG Repeat Length and Age of Onset of Juvenile-Onset Huntington\u2019s Disease"],"prefix":"10.3390","volume":"10","author":[{"given":"Jordan L.","family":"Schultz","sequence":"first","affiliation":[{"name":"Department of Psychiatry, Carver College of Medicine at the University of Iowa, Iowa City, IA 52242, USA"},{"name":"Department of Neurology, Carver College of Medicine at the University of Iowa, Iowa City, IA 52242, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amelia D.","family":"Moser","sequence":"additional","affiliation":[{"name":"Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8810-1903","authenticated-orcid":false,"given":"Peg C.","family":"Nopoulos","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Carver College of Medicine at the University of Iowa, Iowa City, IA 52242, USA"},{"name":"Department of Neurology, Carver College of Medicine at the University of Iowa, Iowa City, IA 52242, USA"},{"name":"Department of Pediatrics, Carver College of Medicine at the University of Iowa, Iowa City, IA 52242, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"971","DOI":"10.1016\/0092-8674(93)90585-E","article-title":"A novel gene containing a trinucleotide repeat that is expanded and unstable on Huntington\u2019s disease chromosomes","volume":"72","author":"Macdonald","year":"1993","journal-title":"Cell"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1111\/j.1399-0004.2004.00241.x","article-title":"A new model for prediction of the age of onset and penetrance for Huntington\u2019s disease based on CAG length","volume":"65","author":"Langbehn","year":"2004","journal-title":"Clin. 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