Uncompacted myelin lamellae in peripheral nerve biopsy.
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.
Vital
Claude
C
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
Vital
Anne
A
Bouillot
Sandrine
S
Favereaux
Alexandre
A
Lagueny
Alain
A
Ferrer
Xavier
X
Brechenmacher
Christiane
C
Petry
Klaus G
KG
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*
D018993:Myelin P0 Protein; D018992:Myelin-Associated Glycoprotein; D006639:Histidine; D001120:Arginine