title: Familial mixed nephrocalcinosis as a cause of chronic kidney failure: two case reports.
abstract: BACKGROUND
  Nephrocalcinosis consists of the deposition of calcium salts in the renal parenchyma and is considered the mixed form when it involves the renal cortex and medulla. The main etiological agents of this condition are primary hyperparathyroidism, renal tubular acidosis, medullary sponge kidney, hyperoxaluria and taking certain drugs. These factors can lead to hypercalcemia and/or hypercalciuria, which can give rise to nephrocalcinosis.
  
  
  METHODS
  Patient 1 was a 48-year-old Caucasian woman with a history of bilateral nephrocalcinosis causing chronic kidney failure. Imaging examinations (X-ray, ultrasound and computed tomography of the abdomen) revealed extensive calcium deposits in the renal parenchyma, indicating nephrocalcinosis as the causal factor of the disease. Patient 2 is the 45-year-old brother of patient 1. He exhibited an advanced stage of chronic kidney failure. As nephrocalcinosis is considered to have a genetic component, a family investigation revealed this condition in patient 2.
  
  
  CONCLUSIONS
  Nephrocalcinosis may be detected incidentally through diagnostic imaging studies. Whenever possible, treatment should include the base disease that caused the appearance of the calcification, as the precise etiological determination is extremely important.
authors.affiliation: Urology Department, São José do Rio Preto School of Medicine, Avenida Brigadeiro Faria Lima 5416, São José do Rio Preto, SP 15090-000, Brazil. pedro.arruda@hbsaude.com.br.
authors.forename: Pedro Francisco Ferraz
authors.initials: PF
authors.lastname: de Arruda
authors.forename: Márcio
authors.initials: M
authors.lastname: Gatti
authors.forename: José Germano Ferraz
authors.initials: JG
authors.lastname: de Arruda
authors.forename: Fernando Nestor
authors.initials: FN
authors.lastname: Fácio
authors.forename: Luis Cesar Fava
authors.initials: LC
authors.lastname: Spessoto
authors.forename: Laísa Ferraz
authors.initials: LF
authors.lastname: de Arruda
authors.forename: José Maria Pereira
authors.initials: JM
authors.lastname: de Godoy
authors.forename: Moacir Fernandes
authors.initials: MF
authors.lastname: Godoy
mesh_terms: D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D007676:Kidney Failure, Chronic / Q000209:etiology* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009397:Nephrocalcinosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000235:genetics; D035781:Siblings; D014057:Tomography, X-Ray Computed