Biallelic SQSTM1 mutations in early-onset, variably progressive neurodegeneration

Daniela Di Giuda, Serenella Servidei, Guido Alessandro Primiano, Marco Tartaglia, Valentina Muto, Elisabetta Flex, Zachary Kupchinsky, Hamid Galehdari, Mohammadreza Dehghani, Serena Cecchetti, Giovanna Carpentieri, Teresa Rizza, Neda Mazaheri, Alireza Sedaghat, Mohammad Yahya Vahidi Mehrjardi, Alice Traversa, Michela Di Nottia, Maria M. Kousi, Yalda Jamshidi, Andrea CiolfiViviana Caputo, Reza Azizi Malamiri, Francesca Pantaleoni, Simone Martinelli, Aaron R. Jeffries, Jawaher Zeighami, Amir Sherafat, Gholam Reza Shariati, Rosalba Carrozzo, Nicholas Katsanis, Reza Maroofian

Risultato della ricerca: Contributo in rivistaArticolo in rivista

14 Citazioni (Scopus)

Abstract

Objective To characterize clinically and molecularly an early-onset, variably progressive neurodegenerative disorder characterized by a cerebellar syndrome with severe ataxia, gaze palsy, dyskinesia, dystonia, and cognitive decline affecting 11 individuals from 3 consanguineous families. Methods We used whole-exome sequencing (WES) (families 1 and 2) and a combined approach based on homozygosity mapping and WES (family 3). We performed in vitro studies to explore the effect of the nontruncating SQSTM1 mutation on protein function and the effect of impaired SQSTM1 function on autophagy. We analyzed the consequences of sqstm1 down-modulation on the structural integrity of the cerebellum in vivo using zebrafish as a model. Results We identified 3 homozygous inactivating variants, including a splice site substitution (c.301+2T>A) causing aberrant transcript processing and accelerated degradation of a resulting protein lacking exon 2, as well as 2 truncating changes (c.875_876insT and c.934_936delinsTGA). We show that loss of SQSTM1 causes impaired production of ubiquitin-positive protein aggregates in response to misfolded protein stress and decelerated autophagic flux. The consequences of sqstm1 down-modulation on the structural integrity of the cerebellum in zebrafish documented a variable but reproducible phenotype characterized by cerebellum anomalies ranging from depletion of axonal connections to complete atrophy. We provide a detailed clinical characterization of the disorder; the natural history is reported for 2 siblings who have been followed up for >20 years. Conclusions This study offers an accurate clinical characterization of this recently recognized neurodegenerative disorder caused by biallelic inactivating mutations in SQSTM1 and links this phenotype to defective selective autophagy.
Lingua originaleEnglish
pagine (da-a)E319-E330
Numero di pagine11
RivistaNeurology
Volume91
DOI
Stato di pubblicazionePubblicato - 2018

Keywords

  • early-onset neurodegeneration, ataxia, SQSTM1, autophagy, ubiquitined protein aggregates

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