Clinical Classification of Variants in the Valosin-Containing Protein Gene Associated With Multisystem Proteinopathy

Pathogenic variants in the valosin-containing protein ( ) gene cause a phenotypically heterogeneous disorder that includes myopathy, motor neuron disease, Paget disease of the bone, frontotemporal dementia, and parkinsonism termed multisystem proteinopathy. This hallmark pleiotropy makes the classif...

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Published in:	Neurology. Genetics Vol. 9; no. 5; p. e200093
Main Authors:	Schiava, Marianela, Ikenaga, Chiseko, Topf, Ana, Caballero-Ávila, Marta, Chou, Tsui-Fen, Li, Shan, Wang, Feng, Daw, Jil, Stojkovic, Tanya, Villar-Quiles, Rocio, Nishino, Ichizo, Inoue, Michio, Nishimori, Yukako, Saito, Yoshihiko, Katsuno, Masahisa, Noda, Seiya, Ito, Chihiro, Otsuka, Mieko, Nahir, Sruthi, Manousakis, Georgios, Walk, David, Quinn, Colin, Alfano, Lindsay, Sahenk, Zarife, Tasca, Giorgio, Monforte, Mauro, Sabatelli, Mario, Bisogni, Giulia, Oldfors, Anders, Rydeliu, Anna, Pal, Endre, Paradas, Carmen, Velez, Beatriz, De Bleecker, Jan L, Farugia, Maria Elena, Longman, Cheryl, Harms, Matthew B, Ralston, Stuart, Zanoteli, Edmar, Macedo Serafim da Silva, Andre, Sotoca, Javier, Juntas-Morales, Raul, Bevilacqua, Jorge, Balart, Mireya, Talbot, Stuart, Straub, Volker, Guglieri, Michela, Marini-Bettolo, Chiara, Diaz-Manera, Jordi, Weihl, Conrad Chris
Format:	Journal Article
Language:	English
Published:	United States Wolters Kluwer 01-10-2023
Online Access:	Get full text
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Summary:	Pathogenic variants in the valosin-containing protein ( ) gene cause a phenotypically heterogeneous disorder that includes myopathy, motor neuron disease, Paget disease of the bone, frontotemporal dementia, and parkinsonism termed multisystem proteinopathy. This hallmark pleiotropy makes the classification of novel variants challenging. This retrospective study describes and assesses the effect of 19 novel or nonpreviously clinically characterized variants identified in 28 patients (26 unrelated families) in the retrospective VCP International Multicenter Study. A 6-item clinical score was developed to evaluate the phenotypic level of evidence to support the pathogenicity of the novel variants. Each item is allocated a value, a score ranging from 0.5 to 5.5 points. A receiver-operating characteristic curve was used to identify a cutoff value of 3 to consider a variant as high likelihood disease associated. The scoring system results were confronted with results of in vitro ATPase activity assays and with in silico analysis. All variants were missense, except for one small deletion-insertion, 18 led to amino acid changes within the N and D1 domains, and 13 increased the enzymatic activity. The clinical score coincided with the functional studies in 17 of 19 variants and with the in silico analysis in 12 of 19. For 12 variants, the 3 predictive tools agreed, and for 7 variants, the predictive tools disagreed. The pooled data supported the pathogenicity of 13 of 19 novel VCP variants identified in the study. This study provides data to support pathogenicity of 14 of 19 novel variants and provides guidance for clinicians in the evaluation of novel variants in the gene.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Go to Neurology.org/NG for full disclosures. Funding information is provided at the end of the article. These authors contributed equally to this work. Submitted and externally peer reviewed. The handling editor was Raymond P. Roos, MD, FAAN. The Article Processing Charge was funded by the authors.
ISSN:	2376-7839 2376-7839
DOI:	10.1212/NXG.0000000000200093