{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T09:37:02Z","timestamp":1774517822051,"version":"3.50.1"},"reference-count":12,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,2,25]],"date-time":"2021-02-25T00:00:00Z","timestamp":1614211200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Phelan McDermid syndrome (PMcD) is a neurogenetic disease associated with haploinsufficiency of the SHANK3 gene due to a spectrum of anomalies in the terminal region of the long arm of chromosome 22. SHANK3 is the abbreviation for SH3 domain and ankyrin repeat-containing protein, a gene that encodes for proteins of the postsynaptic density (PSD) of excitatory synapses. This PSD is relevant for the induction and plasticity of spine and synapse formation as a basis for learning processes and long-term potentiation. Individuals with PMcD present with intellectual disability, muscular hypotonia, and severely delayed or absent speech. Further neuropsychiatric manifestations cover symptoms of the autism spectrum, epilepsy, bipolar disorders, schizophrenia, and regression. Regression is one of the most feared syndromes by relatives of PMcD patients. Current scientific evidence indicates that the onset of regression is variable and affects language, motor skills, activities of daily living and cognition. In the case of regression, patients normally undergo further diagnostics to exclude treatable reasons such as complex-focal seizures or psychiatric comorbidities. Here, we report, for the first time, the case of a young female who developed progressive symptoms of regression and a dystonic-spastic hemiparesis that could be traced back to a comorbid multiple sclerosis and that improved after treatment with methylprednisolone.<\/jats:p>","DOI":"10.3390\/ijms22052311","type":"journal-article","created":{"date-parts":[[2021,2,26]],"date-time":"2021-02-26T02:08:17Z","timestamp":1614305297000},"page":"2311","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Phelan McDermid Syndrome: Multiple Sclerosis as a Rare but Treatable Cause for Regression\u2014A Case Report"],"prefix":"10.3390","volume":"22","author":[{"given":"Sarah","family":"Jesse","sequence":"first","affiliation":[{"name":"Department of Neurology, Ulm University, 89081 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8831-858X","authenticated-orcid":false,"given":"Jan Philipp","family":"Delling","sequence":"additional","affiliation":[{"name":"Institute of Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Sch\u00f6n","sequence":"additional","affiliation":[{"name":"Institute of Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tobias M","family":"Boeckers","sequence":"additional","affiliation":[{"name":"Institute of Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany"},{"name":"Deutsches Zentrum f\u00fcr Neurodegenerative Erkrankungen (DZNE), 89081 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Albert","family":"Ludolph","sequence":"additional","affiliation":[{"name":"Department of Neurology, Ulm University, 89081 Ulm, Germany"},{"name":"Deutsches Zentrum f\u00fcr Neurodegenerative Erkrankungen (DZNE), 89081 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2737-7495","authenticated-orcid":false,"given":"Makbule","family":"Senel","sequence":"additional","affiliation":[{"name":"Department of Neurology, Ulm University, 89081 Ulm, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1186\/s13229-019-0291-3","article-title":"Neuropsychiatric decompensation in adolescents and adults with Phelan-McDermid syndrome: A systematic review of the literature","volume":"10","author":"Kolevzon","year":"2019","journal-title":"Mol. Autism"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/j.jpsychires.2017.03.010","article-title":"Characterizing regression in Phelan McDermid Syndrome (22q13 deletion syndrome)","volume":"91","author":"Reierson","year":"2017","journal-title":"J. Psychiatr. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1159\/000503840","article-title":"Deep Phenotyping of Development, Communication and Behaviour in Phelan-McDermid Syndrome","volume":"10","author":"Droogmans","year":"2020","journal-title":"Mol. Syndromol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"103751","DOI":"10.1016\/j.ejmg.2019.103751","article-title":"A longitudinal perspective on the pharmacotherapy of 24 adult patients with Phelan McDermid syndrome","volume":"63","author":"Verhoeven","year":"2020","journal-title":"Eur. J. Med. 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Child Neurol., 883073820960308.","DOI":"10.1177\/0883073820960308"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1016\/j.yebeh.2017.11.034","article-title":"Prospective longitudinal overnight video-EEG evaluation in Phelan-McDermid Syndrome","volume":"80","author":"Khan","year":"2018","journal-title":"Epilepsy Behav."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/S1474-4422(17)30470-2","article-title":"Diagnosis of multiple sclerosis: 2017 revisions of the McDonald criteria","volume":"17","author":"Thompson","year":"2018","journal-title":"Lancet Neurol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1007\/s00418-006-0199-9","article-title":"Expression of postsynaptic density proteins of the ProSAP\/Shank family in the thymus","volume":"126","author":"Redecker","year":"2006","journal-title":"Histochem. 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