A De Novo HECW2 Variant in a Patient with Acetazolamide-Responsive Episodic Ataxia

© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature..

To the best of our knowledge, this is the first case to address episodic ataxia (EA) as a possible phenotypic feature of HECW2-related disorder. This single case study describes a 26-year-old female born at term with mild intellectual disability, neonatal hypotonia, and a history of febrile seizures who presented with paroxysmal events since the age of 2. These episodes include frequent falls due to imbalance, dilated pupils, vertigo, diaphoresis, nausea, vomiting, and nystagmus. Brain imaging was normal. A prolonged electroencephalogram (EEG) revealed interictal epileptiform discharges but failed to capture her clinical events. For several years, she was treated for presumed focal seizures with preserved awareness and trialed on adequate dosing of several antiepileptic medications without improvement. After 25 years, given the more prolonged nature of her episodes and the mild interictal cerebellar signs, empiric treatment with acetazolamide was initiated for a presumed diagnosis of EA. Acetazolamide treatment led to a dramatic reduction in event frequency and severity. The initial EA genetic panel was negative. Clinical exome sequence analysis revealed a novel pathogenic de novo missense variant in the HECW2 gene [c.3829 T > C;(p.Tyr1277His)], located in the HECT domain. HECW2 variants are associated with neurodevelopmental delay, hypotonia, and epilepsy. This study expands the genetic and clinical spectrum of HECW2-related disorder and adds EA to the phenotypic spectrum in affected individuals.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:22

Enthalten in:

Cerebellum (London, England) - 22(2023), 5 vom: 20. Okt., Seite 1029-1033

Sprache:

Englisch

Beteiligte Personen:

Tedesco Silva, Leticia Maria [VerfasserIn]
Sharma, Sonali [VerfasserIn]
Schrauwen, Isabelle [VerfasserIn]
Margolesky, Jason [VerfasserIn]
Detyniecki, Kamil [VerfasserIn]

Links:

Volltext

Themen:

Acetazolamide
Adult
Anticonvulsants
Case Reports
EC 2.3.2.26
EC 2.3.2.27
Epilepsy
Episodic ataxia
HECW2
HECW2 protein, human
Journal Article
O3FX965V0I
Ubiquitin-Protein Ligases

Anmerkungen:

Date Completed 08.09.2023

Date Revised 22.09.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s12311-022-01458-5

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM345064887