title: Clinical, neurophysiological and pathological findings of HNPP patients with 17p12 deletion: a single-centre experience.
abstract: BACKGROUND
  Classic clinical manifestations of HNPP are characterized by recurrent painless mononeuropathies, but a minority of patients present with an atypical clinical pattern, including CMT-like neuropathy, acute or chronic inflammatory demyelinating neuropathy-like polyneuropathy, and carpal tunnel syndrome. Electrophysiological examination plays a central role in the diagnosis of HNPP, disclosing a non-uniform conduction slowing, more pronounced at entrapment sites.
  
  
  METHODS
  We report clinical, electrophysiological and pathological findings from 73 patients with HNPP, coming from 53 unrelated families, followed at our Institute of Neurology over a 20-year period.
  
  
  RESULTS
  Typical presentation with recurrent multiple mononeuropathies was observed in 28/64 (44%) patients. In the remaining 36/64 (56%), we observed an atypical clinical presentation, characterized by generalized weakness and cramps, chronic ulnar neuropathy, carpal tunnel syndrome, chronic sensory polyneuropathy, Guillain-Barrè-like presentation, and CMT-like presentation. Nine patients were asymptomatic for neuropathic symptoms. Nerve conduction studies showed in all cases a sensori-motor demyelinating polyneuropathy with conduction abnormalities preferentially localized at common entrapment sites. When performed, sural nerve biopsy disclosed the focal thickening of the myelin sheath in all patients.
  
  
  CONCLUSIONS
  About half of the patients with HNPP from our cohort showed an atypical clinical presentation. Neurophysiological examination represents the main tool for a proper diagnosis.
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy. Electronic address: mluigetti@gmail.com.
authors.forename: Marco
authors.initials: M
authors.lastname: Luigetti
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Del Grande
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Amelia
authors.initials: A
authors.lastname: Conte
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Lo Monaco
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Bisogni
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Romano
authors.affiliation: Institute of Medical Genetics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Zollino
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy; IRCCS, S. Raffaele-Pisana, Rome, Italy; Casa di Cura, S. Raffaele Cassino, Cassino, Italy.
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
authors.affiliation: Dept. of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Sabatelli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002872:Chromosome Deletion; D002886:Chromosomes, Human, Pair 17; D015331:Cohort Studies; D005260:Female; D015417:Hereditary Sensory and Motor Neuropathy / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000235:genetics / Q000502:physiology; D010525:Peripheral Nerves / Q000503:physiopathology*; D058496:Smith-Magenis Syndrome; D055815:Young Adult
keywords: Clinical phenotype; Hereditary neuropathy with liability to pressure palsies (HNPP); Inherited neuropathy; Neurophysiology; Sural nerve biopsy; Tomaculae