title: Familial hypokalemia/hypomagnesemia and chondrocalcinosis.
abstract: OBJECTIVE
  Familial occurrence of Bartter's syndrome is well known, but the simultaneous occurrence of hypokalemia/hypomagnesemia and chondrocalcinosis in one family has not been described. We present the clinical, laboratory and radiological findings of a family, in which 7 members were affected by disease.
  
  
  METHODS
  A total of 43 members of the family could be interviewed concerning their general health, past diseases and joint complaints. Serum potassium and magnesium were determined in all and radiographic studies were performed in those who had hypokalemia and hypomagnesemia or those with merely articular complaints. Urinary excretion of potassium, magnesium and calcium were determined in the affected persons.
  
  
  RESULTS
  Seven patients were found with hypokalemia and hypomagnesemia. Urinary potassium and magnesium excretion was inappropriately high when compared to the serum levels of these electrolytes. All patients had hypocalciuria and extensive chondrocalcinosis, mainly in the knees, elbows and shoulders. In one patient, most probably as a result of magnesium supplementation, a striking reduction of chondrocalcinosis was observed during a followup of 10 years.
  
  
  CONCLUSIONS
  A family with familial hypokalemia/hypomagnesemia and chondrocalcinosis is described. The reduction of chondrocalcinosis, after years of magnesium supplementation in one patient, suggests that hypomagnesemia is an important factor in the pathogenesis of chondrocalcinosis in these patients.
authors.affiliation: Department of Nephrology, Bosch Medicentrum, 's Hertogenbosch, The Netherlands.
authors.forename: T J
authors.initials: TJ
authors.lastname: Smilde
authors.forename: J F
authors.initials: JF
authors.lastname: Haverman
authors.forename: P
authors.initials: P
authors.lastname: Schipper
authors.forename: A R
authors.initials: AR
authors.lastname: Hermus
authors.forename: F J
authors.initials: FJ
authors.lastname: van Liebergen
authors.forename: J L
authors.initials: JL
authors.lastname: Jansen
authors.forename: P W
authors.initials: PW
authors.lastname: Kloppenborg
authors.forename: M I
authors.initials: MI
authors.lastname: Koolen
mesh_terms: D000328:Adult; D001477:Bartter Syndrome / Q000097:blood / Q000000981:diagnostic imaging / Q000235:genetics* / Q000652:urine; D002805:Chondrocalcinosis / Q000097:blood / Q000000981:diagnostic imaging / Q000235:genetics* / Q000652:urine; D004573:Electrolytes / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007008:Hypokalemia / Q000097:blood / Q000235:genetics* / Q000652:urine; D008274:Magnesium / Q000097:blood* / Q000652:urine; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011188:Potassium / Q000652:urine; D011859:Radiography
chemical_list: D004573:Electrolytes; D008274:Magnesium; D011188:Potassium