title: Arthropathy-related pain in a patient with congenital impairment of pain sensation due to hereditary sensory and autonomic neuropathy type II with a rare mutation in the WNK1/HSN2 gene: a case report.
abstract: BACKGROUND
  Hereditary sensory and autonomic neuropathy (HSAN) type II with WNK1/HSN2 gene mutation is a rare disease characterized by early-onset demyelination sensory loss and skin ulceration. To the best of our knowledge, no cases of an autonomic disorder have been reported clearly in a patient with WNK/HSN2 gene mutation and only one case of a Japanese patient with the WNK/HSN2 gene mutation of HSAN type II was previously reported.
  
  
  METHODS
  Here we describe a 54-year-old woman who had an early childhood onset of insensitivity to pain; superficial, vibration, and proprioception sensation disturbances; and several symptoms of autonomic failure (e.g., orthostatic hypotension, fluctuation in body temperature, and lack of urge to defecate). Genetic analyses revealed compound homozygous mutations in the WNK1/HSN2 gene (c.3237_3238insT; p.Asp1080fsX1). The patient demonstrated sensory loss in the "stocking and glove distribution" but could perceive visceral pain, such as menstrual or gastroenteritis pain. She experienced frequent fainting episodes. She had undergone exenteration of the left metatarsal because of metatarsal osteomyelitis at 18 years. Sural nerve biopsy revealed a severe loss of myelinated and unmyelinated nerves. She complained of severe pain in multiple joints, even on having pain impairment. Although non-steroidal anti-inflammatory drugs are generally more effective than acetaminophen for arthritis, in our case, they were ineffective and acetaminophen (2400 mg/day) adequately controlled her pain and improved quality of life. Over 3 months, the numerical rating scale, pain interference scale of the Brief Pain Inventory, and the Pain Catastrophizing Scale decreased from 6/10 to 3/10, from 52/70 to 20/70, and from 22/52 to 3/52 points, respectively.
  
  
  CONCLUSIONS
  This is the second reported case of a Japanese patient with WNK/HSN2 gene mutation of HSAN type II and the first reported case of an autonomic disorder in a patient with the WNK/HSN2 gene mutation. Acetaminophen adequately controlled arthropathy related pain in a patient with congenital impairment of pain sensation.
authors.affiliation: Center for Pain Management, Osaka University Hospital, 2-15 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan.|Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Junhui
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Department of Neuromodulation, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan.
authors.forename: Tomoo
authors.initials: T
authors.lastname: Mano
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takashima
authors.affiliation: Center for Pain Management, Osaka University Hospital, 2-15 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan. mshibata@pain.med.osaka-u.ac.jp.|Department of Pain Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan. mshibata@pain.med.osaka-u.ac.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shibata
mesh_terms: D018771:Arthralgia / Q000503:physiopathology*; D005260:Female; D009477:Hereditary Sensory and Autonomic Neuropathies / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D007564:Japan; D008875:Middle Aged; D015778:Minor Histocompatibility Antigens / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D013001:Somatoform Disorders / Q000209:etiology / Q000235:genetics / Q000503:physiopathology*; D000076204:WNK Lysine-Deficient Protein Kinase 1
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015778:Minor Histocompatibility Antigens; D017346:Protein Serine-Threonine Kinases; D000076204:WNK Lysine-Deficient Protein Kinase 1; C498743:WNK1 protein, human
keywords: Acetaminophen; Arthropathy; Case report; Demyelinating diseases; Hereditary sensory and autonomic neuropathies