RFC1 repeat expansions: A recurrent cause of sensory and autonomic neuropathy with cough and ataxia.
RFC1 repeat-primed PCR
afferent ataxia
autonomic dysfunction
chronic cough
next-generation sequencing
Journal
European journal of neurology
ISSN: 1468-1331
Titre abrégé: Eur J Neurol
Pays: England
ID NLM: 9506311
Informations de publication
Date de publication:
07 2022
07 2022
Historique:
revised:
20
02
2022
received:
19
01
2022
accepted:
26
02
2022
pubmed:
8
3
2022
medline:
15
6
2022
entrez:
7
3
2022
Statut:
ppublish
Résumé
Ataxia and cough are rare features in hereditary sensory and autonomic neuropathies (HSAN), a group of diseases of mostly unknown genetic cause. Biallelic repeat expansions in RFC1 are associated with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). This study aimed to investigate the prevalence of RFC1 repeat expansions in a cohort of HSAN patients. After unremarkable whole-exome sequencing (WES) analysis, we performed repeat-primed PCR to detect intronic RFC1 expansions in 12 HSAN families, who all presented with chronic cough. In these patients, 75% carried biallelic expansions of the pathogenic AAGGG motif. Compared with RFC1-/- cases, RFC1+/+ cases presented more consistently with positive sensory and autonomic symptoms. Afferent ataxia was more severe in the RFC1+/+ cohort and cerebellar ataxia was a common feature (21%). We demonstrate that RFC1 is a frequent cause of (WES-negative) HSAN with chronic cough and ataxia. The diagnostic yield of RFC1 repeat-primed PCR was surprisingly high, given that HSAN is genetically poorly understood. This combination of HSAN, ataxia, and chronic cough symptoms represents a new nosological entity within the neuropathy-ataxia spectrum.
Sections du résumé
BACKGROUND AND PURPOSE
Ataxia and cough are rare features in hereditary sensory and autonomic neuropathies (HSAN), a group of diseases of mostly unknown genetic cause. Biallelic repeat expansions in RFC1 are associated with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). This study aimed to investigate the prevalence of RFC1 repeat expansions in a cohort of HSAN patients.
METHODS
After unremarkable whole-exome sequencing (WES) analysis, we performed repeat-primed PCR to detect intronic RFC1 expansions in 12 HSAN families, who all presented with chronic cough.
RESULTS
In these patients, 75% carried biallelic expansions of the pathogenic AAGGG motif. Compared with RFC1-/- cases, RFC1+/+ cases presented more consistently with positive sensory and autonomic symptoms. Afferent ataxia was more severe in the RFC1+/+ cohort and cerebellar ataxia was a common feature (21%).
CONCLUSIONS
We demonstrate that RFC1 is a frequent cause of (WES-negative) HSAN with chronic cough and ataxia. The diagnostic yield of RFC1 repeat-primed PCR was surprisingly high, given that HSAN is genetically poorly understood. This combination of HSAN, ataxia, and chronic cough symptoms represents a new nosological entity within the neuropathy-ataxia spectrum.
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural
Langues
eng
Sous-ensembles de citation
IM
Pagination
2156-2161Subventions
Organisme : Medical Research Council
ID : MR/T001712/1
Pays : United Kingdom
Organisme : NINDS NIH HHS
ID : R01 NS072248
Pays : United States
Informations de copyright
© 2022 European Academy of Neurology.
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