Objective: N/A

Background: SGCE myoclonus-dystonia (SGCE-M-D) is a movement disorder characterized by myoclonus and dystonia, primarily affecting the neck, trunk, and upper limbs. Patients may also experience focal or segmental dystonia, with non-motor symptoms such as alcohol abuse, obsessive-compulsive disorder, and anxiety. Symptoms typically manifest by age 20 but can appear anytime from six months to 80 years. We describe a case of a 70-year-old man diagnosed with SGCE through whole exome sequencing.

Method: N/A

Results: The patient, initially presenting to the neurology clinic for “twitching” and “spasms,” reported symptom onset at age 18, with a gradual increase in severity. His quality of life suffered significantly, noting difficulties with object handling and voice involvement. Past evaluations, including a workup 20 years ago, were inconclusive, and he found no relief from valproic acid. He has no effective techniques to suppress his movements. Interestingly, his daughter developed similar symptoms at age 13.

On examination, the patient was of normal height with high arched brows and synophrys. Myoclonus was noted in the torso, arms, head, and vocal cords, alongside slight neck dystonia. Neurological examination showed intact strength and sensation, and an MRI of the brain was unremarkable. A genetic myoclonus syndrome was suspected, leading to a referral for genetic evaluation. Whole genome sequencing revealed a heterozygous variant in the SGCE gene (c.289C>T), likely resulting in premature protein termination (p.Arg97*). The patient was started on clonazepam and zonisamide, resulting in improvement of myoclonus.

Conclusion: This case emphasizes the need for a broad differential diagnosis in complex movement disorders and highlights the importance of considering genetic mutations in undiagnosed neurological syndromes.

References: Klinman E, Gooch C, Perlmutter JS, Davis AA, Maiti B. Novel SGCE Mutation in a Patient With Myoclonus-Dystonia: A Case Report. Neurol Genet. 2024 Mar 7;10(2):e200128. doi: 10.1212/NXG.0000000000200128. PMID: 38486676; PMCID: PMC10932734.
Yoganathan S, Kumar M, Sharma S, Patel S, Danda S, Thomas M. SGCE Myoclonus-Dystonia: An Inherited Movement Disorder. Neurology. 2022 Feb 15;98(7):289. doi: 10.1212/WNL.0000000000013209. Epub 2021 Dec 14. PMID: 34906973.
Raymond D, Saunders-Pullman R, Ozelius L. SGCE Myoclonus-Dystonia. 2003 May 21 [Updated 2020 Jun 4]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1414/
Williams L, Ryan M, Kilbride R, Llamas-Osorio Y. Jaw Clonus: A Rhythmic Oscillatory Movement, but Not Tremor. Tremor Other Hyperkinet Mov (N Y). 2020 Sep 29;10:34. doi: 10.5334/tohm.538. PMID: 33042635; PMCID: PMC7528660.
Goel A, Shree R, Kathuria H, Mehta S, Lal V, Mahesh KV. Teaching Video NeuroImages: Jaw Clonus in Amyotrophic Lateral Sclerosis. Neurology. 2021 May 18;96(20):e2563. doi: 10.1212/WNL.0000000000011127. Epub 2020 Oct 27. PMID: 33109624.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/a-case-of-sgce-myoclonus-dystonia-diagnosed-in-a-70-year-old-male/