title: Uncompacted myelin lamellae in peripheral nerve biopsy.
abstract: Since 1979, the authors have studied 49 peripheral nerve biopsies presenting uncompacted myelin lamellae (UML). Based on the ultrastructural pattern of UML they propose a 3-category classification. The first category includes cases displaying regular UML, which was observed in 43 cases; it was more frequent in 9 cases with polyneuropathy organomegaly endocrinopathy m-protein skin changes (POEMS) syndrome as well as in 1 case of Charcot-Marie-Tooth 1B with a novel point mutation in the P0 gene. The second category consists of cases showing irregular UML, observed in 4 cases with IgM monoclonal gammopathy and anti-myelin-associated glycoprotein (MAG) activity. This group included 1 benign case and 3 B-cell malignant lymphomas. The third category is complex UML, which was present in 2 unrelated patients with an Arg 98 His missense mutation in the P0 protein gene. Irregular and complex UML are respectively related to MAG and P0, which play a crucial role in myelin lamellae compaction and adhesion.
authors.affiliation: Neuropathology Laboratory and Neurobiologie des affections de la myéline, EA2966, Victor Segalen University, 146 rue Léo Saignat, BP 42-33076 Bordeaux Cedex, France. claude.vital@neuropath.u-bordeaux.fr
authors.forename: Claude
authors.initials: C
authors.lastname: Vital
authors.forename: Anne
authors.initials: A
authors.lastname: Vital
authors.forename: Sandrine
authors.initials: S
authors.lastname: Bouillot
authors.forename: Alexandre
authors.initials: A
authors.lastname: Favereaux
authors.forename: Alain
authors.initials: A
authors.lastname: Lagueny
authors.forename: Xavier
authors.initials: X
authors.lastname: Ferrer
authors.forename: Christiane
authors.initials: C
authors.lastname: Brechenmacher
authors.forename: Klaus G
authors.initials: KG
authors.lastname: Petry
mesh_terms: D001120:Arginine / Q000235:genetics; D001706:Biopsy; D002607:Charcot-Marie-Tooth Disease / Q000235:genetics / Q000473:pathology; D006639:Histidine / Q000235:genetics; D006801:Humans; D016393:Lymphoma, B-Cell / Q000473:pathology; D008854:Microscopy, Electron; D009154:Mutation; D018993:Myelin P0 Protein / Q000235:genetics; D009186:Myelin Sheath / Q000145:classification / Q000648:ultrastructure*; D018992:Myelin-Associated Glycoprotein / Q000032:analysis; D016878:POEMS Syndrome / Q000473:pathology; D010265:Paraproteinemias / Q000473:pathology; D010525:Peripheral Nerves / Q000648:ultrastructure*; D010523:Peripheral Nervous System Diseases / Q000235:genetics / Q000473:pathology*
chemical_list: D018993:Myelin P0 Protein; D018992:Myelin-Associated Glycoprotein; D006639:Histidine; D001120:Arginine