{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T05:04:43Z","timestamp":1780463083412,"version":"3.54.1"},"reference-count":21,"publisher":"Springer Science and Business Media LLC","issue":"3","license":[{"start":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T00:00:00Z","timestamp":1778112000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T00:00:00Z","timestamp":1778112000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Cerebellum"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Spinocerebellar ataxia type 27B (SCA27B), caused by an intronic GAA repeat expansion in the\n                    <jats:italic>FGF14<\/jats:italic>\n                    gene, has recently emerged as a major cause of late-onset cerebellar ataxia (LOCA). Its prevalence and clinical profile in Central and Eastern Europe remain largely unknown. To determine the frequency and phenotypic characteristics of\n                    <jats:italic>FGF14<\/jats:italic>\n                    GAA\u00b7TTC repeat expansions, a large cohort of Polish patients with undiagnosed adult-onset cerebellar ataxia was investigated. We retrospectively analyzed 701 patients (age of onset\u2009\u2265\u200925 years) with adult-onset cerebellar ataxia of unknown etiology, previously tested negative for SCA1, SCA2, SCA3, SCA8, and\n                    <jats:italic>RFC1<\/jats:italic>\n                    expansions. GAA\u00b7TTC repeat lengths were assessed using long-range and repeat-primed PCR. Expansions\u2009\u2265\u2009250 repeats were classified as pathogenic. Clinical and MRI data were evaluated where available. A control group of 66 neurologically healthy individuals was also screened. Pathogenic\n                    <jats:italic>FGF14<\/jats:italic>\n                    expansions (\u2265\u2009250 repeats) were identified in 4.4% (31\/701) of patients, including 23 with fully penetrant (\u2265\u2009300) and 8 with incompletely penetrant (250\u2013299) alleles. No pathogenic expansions were found in controls. The mean age of onset was 49.8 years. Common symptoms included balance and gait disturbances, cerebellar syndrome, and episodic features such as diplopia. Cerebellar atrophy was present in 45% of patients with available MRI. No significant correlation between repeat length and age of onset was observed. Our findings confirm that\n                    <jats:italic>FGF14<\/jats:italic>\n                    repeat expansions are an underrecognized cause of LOCA in Poland and support their inclusion in standard genetic testing for adult-onset ataxias. Further studies are warranted to better define penetrance and genotype\u2013phenotype correlations.\n                  <\/jats:p>","DOI":"10.1007\/s12311-026-02003-4","type":"journal-article","created":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T11:32:35Z","timestamp":1778153555000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Identification of FGF14 GAA Expansions in Polish Patients with Undiagnosed Cerebellar Ataxia \u2013 A Preliminary Study"],"prefix":"10.1007","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4310-5091","authenticated-orcid":false,"given":"Marta","family":"Matlawska","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karolina","family":"Ziora-Jakutowicz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marie- Josee","family":"Dicaire","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joanna","family":"Pera","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Pellerin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernard","family":"Brais","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pablo","family":"Iruzubieta","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ewelina","family":"Elert- Dobkowska","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Sulek","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,5,7]]},"reference":[{"issue":"1","key":"2003_CR1","doi-asserted-by":"publisher","first-page":"16","DOI":"10.1007\/s11910-024-01400-8","volume":"16","author":"D Pellerin","year":"2025","unstructured":"Pellerin D, Iruzubieta P, Xu IRL al. Recent Advances in the Genetics of Ataxias: An Update on Novel Autosomal Dominant Repeat Expansions. Curr Neurol Neurosci Rep. 2025;16(1):16.","journal-title":"Curr Neurol Neurosci Rep"},{"key":"2003_CR2","doi-asserted-by":"publisher","first-page":"128","DOI":"10.1056\/NEJMoa2207406","volume":"388","author":"D Pellerin","year":"2023","unstructured":"Pellerin D, Danzi MC, Wilke C, et al. Deep intronic FGF14 GAA repeat expansion in late-onset cerebellar ataxia. N Engl J Med. 2023;388:128\u201341.","journal-title":"N Engl J Med"},{"key":"2003_CR3","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1016\/j.ajhg.2022.11.015","volume":"110","author":"H Rafehi","year":"2023","unstructured":"Rafehi H, Read J, Szmulewicz DJ, et al. An intronic GAA repeat expansion in FGF14 causes the autosomal-dominant adult-onset ataxia SCA50\/ATX-FGF14. Am J Hum Genet. 2023;110:105\u201319.","journal-title":"Am J Hum Genet"},{"key":"2003_CR4","doi-asserted-by":"publisher","first-page":"9737","DOI":"10.1038\/s41598-023-36654-8","volume":"13","author":"C Bonnet","year":"2023","unstructured":"Bonnet C, Pellerin D, Roth V, et al. Optimized testing strategy for the diagnosis of GAA-FGF14 ataxia\/spinocerebellar ataxia 27B. Sci Rep. 2023;13:9737.","journal-title":"Sci Rep"},{"key":"2003_CR5","unstructured":"Pellerin D, Danzi M, Renaud M, et al. In: Adam MP, Feldman J, Mirzaa GM, et al. editors. GAA-FGF14-Related Ataxia. Seattle: GeneReviews\u00ae, University of Washington; 2024. pp. 1993\u20132025."},{"key":"2003_CR6","doi-asserted-by":"publisher","first-page":"e200094","DOI":"10.1212\/NXG.0000000000200094","volume":"9","author":"LE Novis","year":"2023","unstructured":"Novis LE, Frezatti RS, Pellerin D, et al. Frequency of GAA-FGF14 ataxia in a large cohort of Brazilian patients with unsolved adult-onset cerebellar ataxia. Neurol Genet. 2023;9:e200094.","journal-title":"Neurol Genet"},{"key":"2003_CR7","doi-asserted-by":"publisher","first-page":"107067","DOI":"10.1016\/j.parkreldis.2024.107067","volume":"126","author":"O Halstuk","year":"2024","unstructured":"Halstuk O, Dayan R, Silverstein S, et al. Low prevalence of SCA27B in adult-onset cerebellar ataxia cohort of Jewish ancestry. Parkinsonism Relat Disord. 2024;126:107067.","journal-title":"Parkinsonism Relat Disord"},{"key":"2003_CR8","doi-asserted-by":"publisher","first-page":"446","DOI":"10.1111\/cge.14482","volume":"105","author":"C Kartanou","year":"2024","unstructured":"Kartanou C, Mitrousias A, Pellerin D, et al. The FGF14 GAA repeat expansion in Greek patients with late-onset cerebellar ataxia and an overview of the SCA27B phenotype across populations. Clin Genet. 2024;105:446\u201352.","journal-title":"Clin Genet"},{"key":"2003_CR9","doi-asserted-by":"publisher","first-page":"fcae479","DOI":"10.1093\/braincomms\/fcae479","volume":"7","author":"I Livanos","year":"2025","unstructured":"Livanos I, Votsi C, Michailidou K, et al. The FGF14 GAA repeat expansion is a major cause of ataxia in the Cypriot population. Brain Commun. 2025;7:fcae479.","journal-title":"Brain Commun"},{"key":"2003_CR10","doi-asserted-by":"publisher","first-page":"1557","DOI":"10.1002\/mds.29559","volume":"38","author":"H Hengel","year":"2023","unstructured":"Hengel H, Pellerin D, Wilke C, et al. As frequent as polyglutamine spinocerebellar ataxias: SCA27B in a large German autosomal dominant ataxia cohort. 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The protocol was approved by the Local Bioethics Committee at the Institute of Psychiatry and Neurology in Warsaw (resolution no. 30\/2021 November 17, 2021).","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Human Ethics and Consent to Participate"}},{"value":"Informed consent was obtained from all individual participants included in the study.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consents to Participate"}},{"value":"The authors declare no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing Interests"}}],"article-number":"73"}}