title: Primary hyperoxaluria type 1: An underestimated cause of nephrocalcinosis and chronic renal failure in Saudi Arabian children.
abstract: BACKGROUND
  Primary hyperoxaluria type I (PHI) is a rare metabolic disease caused by deficiency or abnormalities of the peroxisomal enzyme alanine-glyoxylate aminotransferase. In the majority of patients, the clinical expression of PHI is characterized by recurrent calcium oxalate urolithiasis, nephrocalcinosis and renal failure.
  
  
  METHODS
  Sixteen children aged 5 months to 14 years were diagnosed as PHI over a 10-year period ending in June 1997. The diagnosis was established by quantitative urinary oxalate excretion, or by a high urine oxalate/creatinine ratio on spot urines.
  
  
  RESULTS
  The majority of patients had nephrolithiasis (13/16) and/or nephrocalcinosis (12/16). Four patients already had advanced chronic renal failure at the time of diagnosis. Altogether, PHI accounted for 20% of nephrocalcinosis and 6% of end-stage renal disease. Two patients had a complete response to pyridoxine therapy, while four patients had a partial response. Eight patients underwent organ transplantation, three underwent kidney transplantation, three received combined liver/kidney transplantation for end-stage renal disease, and two received isolated preemptive liver transplantation.
  
  
  CONCLUSIONS
  Combined organ transplantation provided the best long-term results.
authors.affiliation: Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: S A
authors.initials: SA
authors.lastname: Sanjad
authors.forename: A
authors.initials: A
authors.lastname: Al-Abbad
authors.forename: E
authors.initials: E
authors.lastname: Al-Sabban