Menéndez-González M, García-Martínez A, Fernández-Vega I, Pitiot A, Álvarez V. A variant in GRN of Spanish origin presenting with heterogeneous phenotypes.
Neurologia 2025;
40:57-65. [PMID:
36216226 DOI:
10.1016/j.nrleng.2022.10.001]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023] Open
Abstract
INTRODUCTION
The variant c.1414-1G>T in the GRN gene has previously been reported as probably pathogenic in subjects of Hispanic origin in the American continent.
METHODS
We report 5 families of Spanish origin carrying this variant, including the clinical, neuroimaging, and laboratory findings.
RESULTS
Phenotypes were strikingly different, including cases presenting with behavioral variant frontotemporal dementia, semantic variant primary progressive aphasia, rapidly progressive motor neuron disease (pathologically documented), and tremor-dominant parkinsonism. Retinal degeneration has been found in homozygous carriers only. Ex vivo splicing assays confirmed that the mutation c.1414-1G>T affects the splicing of the exon, causing a loss of 20 amino acids in exon 11.
CONCLUSIONS
We conclude that variant c.1414-1G>T of the GRN gene is pathogenic, can lead to a variety of clinical presentations and to gene dosage effect, and probably has a Spanish founder effect.
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