Acute-onset axonal neuropathy following infection in children with biallelic RCC1 variants: a case series
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Tarih
2025
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Inc
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Background The reasons why some individuals have severe neuropathy following an infection are not known. Through the agnostic screening of children with acute axonal neuropathy after an infection, we identified several families with biallelic variants in RCC1. We aimed to describe the clinical phenotype of these patients, and the molecular and cellular pathology associated with the genetic variants identified in these families. Methods For this case series, we identified children affected by a severe, acute-onset axonal neuropathy following infection through an international research consortium of paediatric neurologists and clinical geneticists from nine countries (Canada, Cyprus, Czechia, Germany, Iran, Saudi Arabia, Slovakia, T & uuml;rkiye, and the UK). Clinical assessments included nerve conduction studies and neuroimaging. We did exome or genome sequencing in DNA samples from all patients. We characterised the proteins encoded by the genetic variants by use of thermal stability and enzymatic assays, using recombinantly expressed proteins. We assessed cellular protein transport under heat or oxidative stress by use of immunofluorescence in primary fibroblasts, obtained from patients. We generated a humanised Drosophila knock-in model to assess the effects of stress on the in vivo function of RCC1. Findings Between Nov 2, 2011, and July 10, 2024, we identified 24 individuals from 12 families who had severe, acute-onset axonal neuropathy following infection (13 female and 11 male patients, with a mean age at diagnosis of 1 year 10 months [SD 227]). Eight biallelic missense variants in RCC1 were identified in affected individuals with autosomal recessive inheritance. Patients had variable phenotypes, ranging from rapidly progressive fatal axonal neuropathy to mild motor neuropathy with impaired walking. Neurological presentation was often secondary to an infection, resulting in initial misdiagnoses of Guillain-Barr & eacute; syndrome in several patients. 15 children had disease recurrence. The disease was fatal in 15 patients. The RCC1 variants in these patients code for proteins that alter GDP-to-GTP exchange activity and have reduced thermal stability in vitro. In primary fibroblasts, heat shock or oxidative stress revealed defects in Ran nuclear localisation and impaired nucleocytoplasmic transport. A Drosophila model of the disease revealed a fatal intolerance to oxidative stress. Interpretation We describe an autosomal recessive, acute-onset paediatric axonal neuropathy, seemingly triggered by infection, that affects individuals with biallelic RCC1 variants. In these children, the disease can mimic Guillain-Barr & eacute; syndrome. The pathological mechanisms underlying this novel axonal neuropathy might overlap with those of amyotrophic lateral sclerosis. Cellular studies indicate that RCC1 variants affect nucleocytoplasmic transport, which is crucial for healthy axonal function. Future studies should be directed at pre-symptomatic treatment by exploring ways to maintain nucleocytoplasmic transport. Copyright (c) 2025 Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.
Açıklama
Anahtar Kelimeler
Guillain-Barre-Syndrome, Cycle Gene Rcc1, Nucleotide Exchange, Nucleocytoplasmic Transport, Oxidative-Stress, Nuclear Export, Drosophila, Ran, Mechanism, Paraquat
Kaynak
Lancet Neurology
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
24
Sayı
8
