Genotype-phenotype relations for episodic ataxia genes: MDSGene systematic review

Diana Angelika Olszewska, Aakash Shetty, Rajasumi Rajalingam, Jon Rodriguez-Antiguedad, Moath Hamed, Jana Huang, Marianthi Breza, Ashar Rasheed, Natascha Bahr, Harutyan Madoev, Ana Westenberger, Joanne Trinh, Katja Lohmann, Christine Klein, Connie Marras, Olga Waln

Abstract

BACKGROUND: Most episodic ataxias (EA) are autosomal dominantly inherited and characterized by recurrent attacks of ataxia and other paroxysmal and non-paroxysmal features. EA is often caused by pathogenic variants in the CACNA1A, KCNA1, PDHA1, and SLC1A3 genes, listed as paroxysmal movement disorders (PxMD) by the MDS Task Force on the Nomenclature of Genetic Movement Disorders. Little is known about the genotype-phenotype correlation of the different genetic EA forms.

METHODS: We performed a systematic review of the literature to identify individuals affected by an episodic movement disorder harboring pathogenic variants in one of the four genes. We applied the standardized MDSGene literature search and data extraction protocol to summarize the clinical and genetic features. All data are available via the MDSGene protocol and platform on the MDSGene website (https://www.mdsgene.org/).

RESULTS: Information on 717 patients (CACNA1A: 491, KCNA1: 125, PDHA1: 90, and SLC1A3: 11) carrying 287 different pathogenic variants from 229 papers was identified and summarized. We show the profound phenotypic variability and overlap leading to the absence of frank genotype-phenotype correlation aside from a few key 'red flags'.

CONCLUSION: Given this overlap, a broad approach to genetic testing using a panel or whole exome or genome approach is most practical in most circumstances.

Original languageEnglish
JournalEuropean Journal of Neurology
Volume30
Issue number10
Pages (from-to)3377-3393
Number of pages17
ISSN1351-5101
DOIs
Publication statusPublished - 10.2023

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