Abstract
Background
Progressive muscular atrophy (PMA) is a rare adult-onset neurological disease that is characterized by isolated lower motor neuron degeneration. While it is still disputable whether PMA is a subtype of amyotrophic lateral sclerosis (ALS) or an isolated disorder, it is well-established as a clinically defined entity. About 5% of PMA cases are monogenic, and the implicated genes largely overlap with those causing monogenic ALS.
Case description
Here we describe a 68-year-old female patient with progressive and asymmetric upper-limb weakness throughout an 18-month period, with muscle atrophy, dysphagia and slurring of speech. The lower limbs were unaffected, and there was no sign of upper motor neuron dysfunction. Comprehensive genetic testing for single nucleotide and copy-number variants revealed a pathogenic monoallelic variant c.1529C>T, p.(Ala510Val) in the SPG7 gene.
Discussion
Pathogenic biallelic SPG7 variants have been originally associated with hereditary spastic paraplegia, but other phenotypes are nowadays known to be linked to these variants, such as ALS. However, there is no report of this (or any) other SPG7 variant in association with PMA, whether it progressed to ALS or not. In conclusion, we present the first known case of PMA associated with a monoallelic SPG7 mutation.
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The authors would like to thank the patient for participating in the study.
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The study was performed in accordance with internal institutional ethical guidelines from Centro Hospitalar e Universitário de Santo António for case reports, which requires informed consent from all patients/supervisors for the work and its publication.
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Pereira, Â., Tkachenko, N., Fortuna, A.M. et al. An SPG7 mutation as a novel cause of monogenic progressive muscular atrophy. Neurol Sci 44, 3303–3305 (2023). https://doi.org/10.1007/s10072-023-06867-w
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DOI: https://doi.org/10.1007/s10072-023-06867-w