An Unusual Case of Progressive Myoclonic Epilepsy (PME): Familial Encephalopathy with Neuroserpin Inclusion Body (FENIB)

Abstract

Progressive myoclonic epilepsy (PME) is a spectrum with epileptic encephalopathy and myoclonus. In this case report authors describe a young patient presenting with refractory multifocal myoclonus with multiple seizure types with dyscognitive features. He was bed-bound with complete dependency on his caregivers. His electroencephalogram had an encephalopathy pattern, and his magnetic resonance imaging showed gross cortical atrophy. In this patient, the working clinical diagnosis of epileptic encephalopathy with PME phenotype had a wide differential list including neuronal ceroid lipofuscinosis, Lafora body disease, sialidosis, myoclonic epilepsy with ragged red fibers, dentatorubro-pallidoluysian atrophy, Unverricht–Lundborg, and other rare disorders such as Gaucher's disease and other genetic causes. Eventually after ruling out all common etiologies, whole-exome sequencing revealed a SERPINI1 gene mutation in exon 9 showing a pathogenic variant c1175G > A (p.Gly392Glu) which associated with PME as a part of familial encephalopathy with neuroserpin inclusion bodies.

Keywords

myoclonic epilepsy - neuroserpin - encephalopathy

Patient Consent

A full and detailed consent from the guardian has been taken. The patient's identity has been adequately anonymized. If anything related to the patient's identity is shown, adequate consent has been taken from the guardian.

Note

The authors hereby certify that the work shown here is genuine, original, and not submitted anywhere, either in part or full.

Publication History

Received: 06 February 2023

Accepted: 20 April 2023

Article published online:
26 May 2023

• References

• 1 Davis R, Collins G. Familial Encephalopathy with Neuroserpin Inclusion Bodies. Neurodegeneration: The Molecular Pathology of Dementia and Movement Disorders 2nd ed. West Sussex, UK: Wiley-Blackwell. 2011: 456-460
• 2 Westmoreland BF, Klass DW, Sharbrough FW, Reagan TJ. Alpha-coma. Electroencephalographic, clinical, pathologic, and etiologic correlations. Arch Neurol 1975; 32 (11) 713-718
• 3 Orsini A, Valetto A, Bertini V. et al. The best evidence for progressive myoclonic epilepsy: a pathway to precision therapy. Seizure 2019; 71: 247-257
• 4 Kälviäinen R. Progressive myoclonus epilepsies. Semin Neurol 2015; 35 (03) 293-299
• 5 Hagen MC, Murrell JR, Delisle MB. et al. Encephalopathy with neuroserpin inclusion bodies presenting as progressive myoclonus epilepsy and associated with a novel mutation in the Proteinase Inhibitor 12 gene. Brain Pathol 2011; 21 (05) 575-582
• 6 Coutelier M, Andries S, Ghariani S. et al. Neuroserpin mutation causes electrical status epilepticus of slow-wave sleep. Neurology 2008; 71 (01) 64-66
• 7 Davis RL, Holohan PD, Shrimpton AE. et al. Familial encephalopathy with neuroserpin inclusion bodies. Am J Pathol 1999; 155 (06) 1901-1913
• 8 D'Acunto E, Fra A, Visentin C. et al. Neuroserpin: structure, function, physiology and pathology. Cell Mol Life Sci 2021; 78 (19-20): 6409-6430
• 9 Takao M, Benson MD, Murrell JR. et al. Neuroserpin mutation S52R causes neuroserpin accumulation in neurons and is associated with progressive myoclonus epilepsy. J Neuropathol Exp Neurol 2000; 59 (12) 1070-1086
• 10 Potempa J, Korzus E, Travis J. The serpin superfamily of proteinase inhibitors: structure, function, and regulation. J Biol Chem 1994; 269 (23) 15957-15960
• 11 Gourfinkel-An I, Duyckaerts C, Camuzat A. et al. Clinical and neuropathologic study of a French family with a mutation in the neuroserpin gene. Neurology 2007; 69 (01) 79-83