title: Pediatric urolithiasis in a non-endemic country: a single center experience from The Netherlands.
abstract: OBJECTIVE
  To provide insight in causative factors of pediatric urolithiasis in The Netherlands, a non-endemic country.
  
  
  METHODS
  Data from 71 children with urolithiasis and stone analyses between 1996 and 2010 in the Radboud University Nijmegen Medical Centre were studied retrospectively. Patients (48 boys, 23 girls, ratio 2.1:1) were aged 0.5-18.3 years (mean 8.8, SD 5.6). All stone analyses were performed with FTIR spectroscopy.
  
  
  RESULTS
  Of the 49 patients with metabolic analysis, 78% showed one (n = 15) or more (n = 23) metabolic abnormalities. Forty-seven percent had hypercalciuria (n = 23), 31% had hyperoxaluria (n = 15), 29% hypocitraturia (n = 14), 10% hyperuricosuria (n = 5), 10% cystinuria (n = 5), and 6% had hypomagnesiuria (n = 3). Sixty-one percent of the stones were composed of calcium phosphate, calcium oxalate, or a combination of those. Twenty-six percent consisted of pure or mixed magnesium ammonium phosphate, 8.3% pure or mixed urate, and 8.3% cystine.
  
  
  CONCLUSIONS
  Children with urolithiasis in The Netherlands show stone composition similar to other Western European countries. However, a high percentage of metabolic abnormalities (78%) was found, indicating the need for extensive evaluation of pediatric urolithiasis to find underlying causes and thereby prevent stone recurrences. A close collaboration between a pediatric nephrologist and urologist is mandatory for optimal surgical and medical treatment.
authors: Department of Pediatric Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors: Daphne M
authors: DM
authors: Rellum
authors: Department of Urology, Pediatric Urology Centre, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors: Wout F
authors: WF
authors: Feitz
authors: Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors: Antonius E
authors: AE
authors: van Herwaarden
authors: Department of Pediatric Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. Electronic address: m.schreuder@cukz.umcn.nl.
authors: Michiel F
authors: MF
authors: Schreuder
mesh_terms: D000293:Adolescent; D002129:Calcium Oxalate / Q000032:analysis; D002130:Calcium Phosphates / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D014545:Urinary Calculi / Q000737:chemistry; D052878:Urolithiasis / Q000209:etiology* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002130:Calcium Phosphates; D002129:Calcium Oxalate; C020243:calcium phosphate
keywords: Children; Hypercalciuria; Hypocitraturia; Urolithiasis