title: Mild infantile hypercalcemia: diagnostic tests and outcomes.
abstract: OBJECTIVE
  To assess outcome in a cohort of patients with infantile hypercalcemia followed over 3 years.
  
  
  METHODS
  Patients (n = 32) presenting to the calcium clinic between July 2002 and September 2008 were studied. In addition to tests of calcium phosphate metabolism, serum insulin-like growth factor-1, calcitonin, urine citrate, and calcium-sensing receptor gene analysis were obtained.
  
  
  RESULTS
  Mean age at presentation was 6.0 ± 6.3 months. Mean calcium level was 11.4 ± 0.7 mg/dL (2.84 ± 0.17 mmol/L). A recognized cause was found in 14% and a probable cause in 14% of the cohort. Those with nephrocalcinosis (n = 11) had significantly lower mean weight SDS and higher mean calcium levels. The biochemical profile of those in whom no cause could be determined included nonsuppressed parathyroid hormone with either normal or increased 1,25(OH)(2)D. Hypercalcemia resolved in 20 patients. However, in approximately a third, there was persistence in hypercalcemia, hypercalciuria, or nephrocalcinosis.
  
  
  CONCLUSIONS
  The addition of 1,25(OH)(2)D and calcium-sensing receptor mutation analysis to a panel of investigations may improve diagnostic yield. Clinical outcome is overall good, however, one-third need ongoing follow-up.
authors.affiliation: Division of Endocrinology, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Dror
authors.initials: D
authors.lastname: Koltin
authors.forename: Marianna
authors.initials: M
authors.lastname: Rachmiel
authors.forename: Betty Y L
authors.initials: BY
authors.lastname: Wong
authors.forename: David E C
authors.initials: DE
authors.lastname: Cole
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Harvey
authors.forename: Etienne
authors.initials: E
authors.lastname: Sochett
mesh_terms: D002118:Calcium / Q000097:blood*; D002130:Calcium Phosphates / Q000097:blood*; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D004252:DNA Mutational Analysis; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D007223:Infant; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009154:Mutation; D010281:Parathyroid Hormone / Q000097:blood; D011863:Radioimmunoassay; D044169:Receptors, Calcium-Sensing / Q000235:genetics; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013053:Spectrophotometry; D013997:Time Factors
chemical_list: C095550:CASR protein, human; D002130:Calcium Phosphates; D010281:Parathyroid Hormone; D044169:Receptors, Calcium-Sensing; D007334:Insulin-Like Growth Factor I; C020243:calcium phosphate; D002118:Calcium