biostudies-literatureChun MYYonsei University College of MedicineTakeda Science FoundationJapan Agency for Medical Research and DevelopmentInstitute of Information & Communications Technology Planning & EvaluationNational Research Foundation of KoreaJapan Society for the Promotion of ScienceSamsung Medical Center315-324https://www.ebi.ac.uk/biostudies/studies/S-EPMC12303689biostudies-literatureUnknown21(4)<h4>Background and purpose</h4>Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative disease characterized by a wide range of clinical manifestations. GGC-repeat expansion in <i>NOTCH2NLC</i> was recently identified as the genetic cause of NIID. Here we report clinical, radiological, pathological, and genetic findings in NIID patients.<h4>Methods</h4>Twenty-five NIID patients from 22 unrelated families of Korean ancestry were reviewed from 9 referral centers in South Korea. We compared clinical features between sporadic and familial NIID patients. We classified NIID patients according to their prominent symptoms. The presence of GGC repeat expansion was analyzed in 19 patients.<h4>Results</h4>The 25 reviewed NIID patients comprised 12 (48.0%) sporadic and 13 (52Journal of clinical neurology (Seoul, Korea)Diverse Clinical Phenotypes of Neuronal Intranuclear Inclusion Disease in South Korea.PMC12303689JP24ek0109677JP23K275686-2023-0145JP24ek0109674JP24ek0109760RS-2020-II201821JP24K02230JP24ek0109617RS-2022-NR070487JP24ek0109648SMX1250081Yoon SJNa DLJeong JHLee JESeo SWKim EJLee JYoun JKim JMizuguchi TSuh YLPark JYJang JHLee NKJeong HPark JLee KBKim HJJang HYang TWPark SKim SChun MYLee SYJung NYKameyama SKim HCLee EHOh EMatsumoto NfalseDiverse Clinical Phenotypes of Neuronal Intranuclear Inclusion Disease in South Korea.<h4>Background and purpose</h4>Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative disease characterized by a wide range of clinical manifestations. GGC-repeat expansion in <i>NOTCH2NLC</i> was recently identified as the genetic cause of NIID. Here we report clinical, radiological, pathological, and genetic findings in NIID patients.<h4>Methods</h4>Twenty-five NIID patients from 22 unrelated families of Korean ancestry were reviewed from 9 referral centers in South Korea. We compared clinical features between sporadic and familial NIID patients. We classified NIID patients according to their prominent symptoms. The presence of GGC repeat expansion was analyzed in 19 patients.<h4>Results</h4>The 25 reviewed NIID patients comprised 12 (48.0%) sporadic and 13 (522025-01-01T00:00:00Z2025 Jul2026-03-16T08:47:44.164Z2025-08-17T03:05:52.272ZS-EPMC123036894063553610.3988/jcn.2024.0526