title: Underexpression of messenger RNA for peripheral myelin protein 22 in hereditary neuropathy with liability to pressure palsies.
abstract: Hereditary neuropathy with liability to pressure palsies (HNPP) is associated with a deletion in chromosome 17p11.2, including the gene for the peripheral myelin protein 22 (PMP-22). Because of the proposal that a decreased dosage of the PMP-22 gene was the cause of HNPP, we evaluated sural nerves from eight patients with the 17p11.2 deletion and from five normal controls. The relative amount of PMP-22 mRNA was significantly lower in HNPP patients compared with normal controls (p < 0.02) using a semiquantitative reverse transcriptase-polymerase chain reaction. There was no significant decrease of Pzero mRNA. Sural nerves from HNPP patients showed normal immunostaining with monoclonal antibodies against PMP-22, Pzero, and myelin basic protein, and only rare myelinated fibers, classified as "tomacula," showed a patchy staining of the compact myelin with monoclonal antibody against PMP-22. The significant underexpression of PMP-22 mRNA in HNPP patients compared with normal controls demonstrates that a decreased dosage of the PMP-22 gene is the most likely pathogenetic mechanism in HNPP.
authors.affiliation: Department of Neurological Sciences, University of Genoa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Schenone
authors.forename: L
authors.initials: L
authors.lastname: Nobbio
authors.forename: P
authors.initials: P
authors.lastname: Mandich
authors.forename: E
authors.initials: E
authors.lastname: Bellone
authors.forename: M
authors.initials: M
authors.lastname: Abbruzzese
authors.forename: F
authors.initials: F
authors.lastname: Aymar
authors.forename: G L
authors.initials: GL
authors.lastname: Mancardi
authors.forename: A J
authors.initials: AJ
authors.lastname: Windebank
mesh_terms: D001483:Base Sequence; D004487:Edema / Q000473:pathology; D030342:Genetic Diseases, Inborn / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008969:Molecular Sequence Data; D009185:Myelin Proteins / Q000235:genetics*; D009186:Myelin Sheath; D010243:Paralysis / Q000235:genetics* / Q000473:pathology; D010523:Peripheral Nervous System Diseases / Q000235:genetics* / Q000473:pathology; D011312:Pressure; D012333:RNA, Messenger / Q000235:genetics*; D012008:Recurrence
chemical_list: D009185:Myelin Proteins; C073687:PMP22 protein, human; D012333:RNA, Messenger