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Intermediate alleles (IAs, CAG\u2009=\u200927\u201335) are generally not associated with HD. However, IA carriers with symptoms have been reported in literature.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To review the existing literature on IAs, in order to provide an overview of the clinical phenotype of IA carriers.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Peer-reviewed articles published between 1993 and July 2024 from three databases (Embase, PubMed, and Web of Science) were included.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>In case reports, a high percentage (90%) of IA carriers was reported to have symptoms (HD-related and -unrelated), or abnormalities in neuroimaging. Cohort studies also reported evidence of symptoms in IA carriers, although most cohorts did not obtain significant differences compared to controls.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      Based on this review, we argue that there is not enough evidence to draw a clear conclusion on the clinical phenotype of individuals carrying an intermediate allele of the\n                      <jats:italic toggle=\"yes\">HTT<\/jats:italic>\n                      gene. Literature reports symptomatic IA carriers, but reported symptoms are non-specific and common in the general population. Additionally, the quality of the data is suboptimal, due to lack of detailed symptom descriptions, the absence of differential diagnoses, a selection bias, and a considerable publication bias towards IA carriers with symptoms. More research is needed to provide a better insight into the clinical phenotype of IA carriers.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/18796397251397683","type":"journal-article","created":{"date-parts":[[2025,12,17]],"date-time":"2025-12-17T18:34:08Z","timestamp":1765996448000},"page":"3-19","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["The clinical phenotype of carriers of intermediate alleles in the huntingtin gene: A scoping review"],"prefix":"10.1177","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6646-4102","authenticated-orcid":false,"given":"Anna","family":"van Hofslot","sequence":"first","affiliation":[{"name":"Medicine"},{"name":"Maastricht University"},{"name":"Maastricht University Medical Centre"},{"name":"Leiden University Medical Centre"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0732-4406","authenticated-orcid":false,"given":"Mayke","family":"Oosterloo","sequence":"additional","affiliation":[{"name":"Medicine"},{"name":"Maastricht University"},{"name":"Maastricht University Medical Centre"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4469-0763","authenticated-orcid":false,"given":"Joost J.A.","family":"de Jong","sequence":"additional","affiliation":[{"name":"Medicine"},{"name":"Maastricht University"},{"name":"Maastricht University Medical Center"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6337-0952","authenticated-orcid":false,"given":"Ruben L.","family":"Andriessen","sequence":"additional","affiliation":[{"name":"Medicine"},{"name":"Maastricht University"},{"name":"Maastricht University Medical Centre"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3512-2468","authenticated-orcid":false,"given":"Susanne T.","family":"de Bot","sequence":"additional","affiliation":[{"name":"Leiden University Medical Centre"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5638-9292","authenticated-orcid":false,"given":"David E. 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