TY - JOUR
T1 - Differences in Motor Features of C9orf72, MAPT, or GRN Variant Carriers With Familial Frontotemporal Lobar Degeneration
AU - Tipton, Philip Wade
AU - Deutschlaender, Angela B.
AU - Savica, Rodolfo
AU - Heckman, Michael G.
AU - Brushaber, Danielle E.
AU - Dickerson, Bradford C.
AU - Gavrilova, Ralitza H.
AU - Geschwind, Daniel H.
AU - Ghoshal, Nupur
AU - Graff-Radford, Jonathan
AU - Graff-Radford, Neill R.
AU - Grossman, Murray
AU - Hsiung, Ging Yuek R.
AU - Huey, Edward D.
AU - Irwin, David John
AU - Jones, David T.
AU - Knopman, David S.
AU - Mcginnis, Scott M.
AU - Rademakers, Rosa
AU - Ramos, Eliana Marisa
AU - Forsberg, Leah K.
AU - Heuer, Hilary W.
AU - Onyike, Chiadi
AU - Tartaglia, Carmela
AU - Domoto-Reilly, Kimiko
AU - Roberson, Erik D.
AU - Mendez, Mario F.
AU - Litvan, Irene
AU - Appleby, Brian S.
AU - Grant, Ian
AU - Kaufer, Daniel
AU - Boxer, Adam L.
AU - Rosen, Howard J.
AU - Boeve, Brad F.
AU - Wszolek, Zbigniew K.
N1 - Publisher Copyright:
© 2022 American Academy of Neurology.
PY - 2022/9/13
Y1 - 2022/9/13
N2 - Background and ObjectivesFamilial frontotemporal lobar degeneration (f-FTLD) is a phenotypically heterogeneous spectrum of neurodegenerative disorders most often caused by variants within chromosome 9 open reading frame 72 (C9orf72), microtubule-associated protein tau (MAPT), or granulin (GRN). The phenotypic association with each of these genes is incompletely understood. We hypothesized that the frequency of specific clinical features would correspond with different genes.MethodsWe screened the Advancing Research and Treatment in Frontotemporal Lobar Degeneration (ARTFL)/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects (LEFFTDS)/ARTFL LEFFTDS Longitudinal Frontotemporal Lobar Degeneration Consortium for symptomatic carriers of pathogenic variants in C9orf72, MAPT, or GRN. We assessed for clinical differences among these 3 groups based on data recorded as part of a detailed neurologic examination, the Progressive Supranuclear Palsy Rating Scale, Progressive Supranuclear Palsy-Quality of Life Rating Scale, Unified Parkinson's Disease Rating Scale Part III (motor items), and the Amyotrophic Lateral Sclerosis Functional Rating Scale, revised version. Data were analyzed using Kruskal-Wallis and Wilcoxon rank-sum tests and Fisher exact test.ResultsWe identified 184 symptomatic participants who had a single pathogenic variant in C9orf72 (n = 88), MAPT (n = 53), or GRN (n = 43). Motor symptom age at onset was earliest in the MAPT participants followed by C9orf72, whereas the GRN pathogenic variant carriers developed symptoms later. C9orf72 participants more often had fasciculations, muscle atrophy, and weakness, whereas parkinsonism was less frequent. Vertical oculomotor abnormalities were more common in the MAPT cohort, whereas apraxia and focal limb dystonia occurred more often in participants with GRN variants.DiscussionWe present a large comparative study of motor features in C9orf72, MAPT, and GRN pathogenic variant carriers with symptomatic f-FTLD. Our findings demonstrate characteristic phenotypic differences corresponding with specific gene variants that increase our understanding of the genotype-phenotype relationship in this complex spectrum of neurodegenerative disorders.Trial Registration InformationNCT02365922, NCT02372773, and NCT04363684.
AB - Background and ObjectivesFamilial frontotemporal lobar degeneration (f-FTLD) is a phenotypically heterogeneous spectrum of neurodegenerative disorders most often caused by variants within chromosome 9 open reading frame 72 (C9orf72), microtubule-associated protein tau (MAPT), or granulin (GRN). The phenotypic association with each of these genes is incompletely understood. We hypothesized that the frequency of specific clinical features would correspond with different genes.MethodsWe screened the Advancing Research and Treatment in Frontotemporal Lobar Degeneration (ARTFL)/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects (LEFFTDS)/ARTFL LEFFTDS Longitudinal Frontotemporal Lobar Degeneration Consortium for symptomatic carriers of pathogenic variants in C9orf72, MAPT, or GRN. We assessed for clinical differences among these 3 groups based on data recorded as part of a detailed neurologic examination, the Progressive Supranuclear Palsy Rating Scale, Progressive Supranuclear Palsy-Quality of Life Rating Scale, Unified Parkinson's Disease Rating Scale Part III (motor items), and the Amyotrophic Lateral Sclerosis Functional Rating Scale, revised version. Data were analyzed using Kruskal-Wallis and Wilcoxon rank-sum tests and Fisher exact test.ResultsWe identified 184 symptomatic participants who had a single pathogenic variant in C9orf72 (n = 88), MAPT (n = 53), or GRN (n = 43). Motor symptom age at onset was earliest in the MAPT participants followed by C9orf72, whereas the GRN pathogenic variant carriers developed symptoms later. C9orf72 participants more often had fasciculations, muscle atrophy, and weakness, whereas parkinsonism was less frequent. Vertical oculomotor abnormalities were more common in the MAPT cohort, whereas apraxia and focal limb dystonia occurred more often in participants with GRN variants.DiscussionWe present a large comparative study of motor features in C9orf72, MAPT, and GRN pathogenic variant carriers with symptomatic f-FTLD. Our findings demonstrate characteristic phenotypic differences corresponding with specific gene variants that increase our understanding of the genotype-phenotype relationship in this complex spectrum of neurodegenerative disorders.Trial Registration InformationNCT02365922, NCT02372773, and NCT04363684.
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U2 - 10.1212/WNL.0000000000200860
DO - 10.1212/WNL.0000000000200860
M3 - Article
C2 - 35790423
AN - SCOPUS:85139739037
SN - 0028-3878
VL - 99
SP - E1154-E1167
JO - Neurology
JF - Neurology
IS - 11
ER -