title: Normal-pressure hydrocephalus: is there a genetic predisposition?
abstract: BACKGROUND
  Normal-pressure hydrocephalus (NPH) is characterized by gait disturbance, cognitive impairment, with or without urinary incontinence, enlarged ventricles with or without cerebral atrophy and normal cerebrospinal fluid pressure.
  
  
  METHODS
  We report two sisters with NPH who lived together their entire lives and whose natural history might provide insights into genetic and environmental mechanisms underlying this disorder. Both patients were in their early seventies, single, had similar daily habits and hypertension. No other family members had NPH.
  
  
  RESULTS
  They both underwent shunt placement and showed improvement documented by history and neuropsychological assessment. Both showed a delayed deterioration due to vasculopathy. Both patients were homozygous for the apolipoprotein E (ApoE) e3 allele on chromosome 19. No environmental factors that might have influenced the development of NPH were identified.
  
  
  CONCLUSIONS
  Our report of two sisters with NPH may indicate the presence of genetic predisposition and further studies involving genetics and environmental factors are necessary to elucidate their role in the pathogenesis of NPH.
authors.affiliation: Department of Surgery, Division of Neurosurgery, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: M D
authors.initials: MD
authors.lastname: Cusimano
authors.forename: D
authors.initials: D
authors.lastname: Rewilak
authors.forename: D T
authors.initials: DT
authors.lastname: Stuss
authors.forename: J C
authors.initials: JC
authors.lastname: Barrera-Martinez
authors.forename: F
authors.initials: F
authors.lastname: Salehi
authors.forename: M
authors.initials: M
authors.lastname: Freedman
mesh_terms: D000368:Aged; D053318:Apolipoprotein E3 / Q000235:genetics; D002888:Chromosomes, Human, Pair 19; D003072:Cognition Disorders / Q000209:etiology / Q000628:therapy; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications / Q000000981:diagnostic imaging / Q000235:genetics / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt / Q000379:methods*
chemical_list: D053318:Apolipoprotein E3