RT info:eu-repo/semantics/article T1 Stroke-Like Episodes and Cerebellar Syndrome in Phosphomannomutase Deficiency (PMM2-CDG): Evidence for Hypoglycosylation-Driven Channelopathy A1 Izquierdo-Serra, Mercè A1 Martínez-Monseny, Antonio A1 López, Laura A1 Carrillo-García, Julia A1 Edo, Albert A1 Ortigoza-Escobar, Juan A1 García, Óscar A1 Cancho-Candela, Ramón A1 Carrasco-Marina, M A1 Gutiérrez-Solana, Luis A1 Cuadras, Daniel A1 Muchart, Jordi A1 Montero, Raquel A1 Artuch, Rafael A1 Pérez-Cerdá, Celia A1 Pérez, Belén A1 Pérez-Dueñas, Belén A1 Macaya, Alfons A1 Fernández-Fernández, José A1 Serrano, Mercedes AB Stroke-like episodes (SLE) occur in phosphomannomutase deficiency (PMM2-CDG),and may complicate the course of channelopathies related to Familial Hemiplegic Migraine (FHM)caused by mutations in CACNA1A (encoding CaV2.1 channel). The underlying pathomechanisms areunknown. We analyze clinical variables to detect risk factors for SLE in a series of 43 PMM2-CDGpatients. We explore the hypothesis of abnormal CaV2.1 function due to aberrant N-glycosylation as apotential novel pathomechanism of SLE and ataxia in PMM2-CDG by using whole-cell patch-clamp,N-glycosylation blockade and mutagenesis. Nine SLE were identified. Neuroimages showed nosigns of stroke. Comparison of characteristics between SLE positive versus negative patients’ groupshowed no differences. Acute and chronic phenotypes of patients with PMM2-CDG or CACNA1Achannelopathies show similarities. Hypoglycosylation of both CaV2.1 subunits (α1A and α2α)induced gain-of-function effects on channel gating that mirrored those reported for pathogenicCACNA1A mutations linked to FHM and ataxia. Unoccupied N-glycosylation site N283 at α1Acontributes to a gain-of-function by lessening CaV2.1 inactivation. Hypoglycosylation of the α2δsubunit also participates in the gain-of-function effect by promoting voltage-dependent openingof the CaV2.1 channel. CaV2.1 hypoglycosylation may cause ataxia and SLEs in PMM2-CDGpatients. Aberrant CaV2.1 N-glycosylation as a novel pathomechanism in PMM2-CDG opens newtherapeutic possibilities PB MDPI YR 2018 FD 2018 LK https://uvadoc.uva.es/handle/10324/64723 UL https://uvadoc.uva.es/handle/10324/64723 LA spa NO International Journal of Molecular Sciences 2018. 2018 Feb 22;19(2). pii: E619 NO Producción Científica DS UVaDOC RD 06-ago-2024