title: Hypercalcemia in Patients with Williams-Beuren Syndrome.
abstract: OBJECTIVE
  To evaluate the timing, trajectory, and implications of hypercalcemia in Williams-Beuren syndrome (WBS) through a multicenter retrospective study.
  
  
  METHODS
  Data on plasma calcium levels from 232 subjects with WBS aged 0-67.1 years were compared with that in controls and also with available normative data. Association testing was used to identify relevant comorbidities.
  
  
  RESULTS
  On average, individuals with WBS had higher plasma calcium levels than controls, but 86.7% of values were normal. Nonpediatric laboratories overreport hypercalcemia in small children. When pediatric reference intervals were applied, the occurrence of hypercalcemia dropped by 51% in infants and by 38% in toddlers. Across all ages, 6.1% of the subjects had actionable hypercalcemia. In children, actionable hypercalcemia was seen in those aged 5-25 months. In older individuals, actionable hypercalcemia was often secondary to another disease process. Evidence of dehydration, hypercalciuria, and nephrocalcinosis were common in both groups. Future hypercalcemia could not be reliably predicted by screening calcium levels. A subgroup analysis of 91 subjects found no associations between hypercalcemia and cardiovascular disease, gastrointestinal complaints, or renal anomalies. Analyses of electrogradiography data showed an inverse correlation of calcium concentration with corrected QT interval, but no acute life-threatening events were reported.
  
  
  CONCLUSIONS
  Actionable hypercalcemia in patients with WBS occurs infrequently. Although irritability and lethargy were commonly reported, no mortality or acute life-threatening events were associated with hypercalcemia and the only statistically associated morbidities were dehydration, hypercalciuria, and nephrocalcinosis.
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors: Sampat
authors: S
authors: Sindhar
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors: Michael
authors: M
authors: Lugo
authors: National Institutes of Health, National Heart, Lung, and Blood Institute, Bethesda, MD.
authors: Mark D
authors: MD
authors: Levin
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors: Joshua R
authors: JR
authors: Danback
authors: Frank H. Netter School of Medicine, Quinnipiac University, North Haven, CT.
authors: Benjamin D
authors: BD
authors: Brink
authors: Frank H. Netter School of Medicine, Quinnipiac University, North Haven, CT.
authors: Eric
authors: E
authors: Yu
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors: Dennis J
authors: DJ
authors: Dietzen
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors: Amy L
authors: AL
authors: Clark
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors: Carolyn A
authors: CA
authors: Purgert
authors: Massachusetts General Hospital, Boston, MA.
authors: Jessica L
authors: JL
authors: Waxler
authors: Section of Cardiology, Departments of Pediatrics and Internal Medicine, Yale University School of Medicine, New Haven, CT.
authors: Robert W
authors: RW
authors: Elder
authors: Frank H. Netter School of Medicine, Quinnipiac University, North Haven, CT; Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
authors: Barbara R
authors: BR
authors: Pober
authors: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO; National Institutes of Health, National Heart, Lung, and Blood Institute, Bethesda, MD. Electronic address: beth.kozel@nih.gov.
authors: Beth A
authors: BA
authors: Kozel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000150:complications* / Q000453:epidemiology; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018980:Williams Syndrome / Q000150:complications*; D055815:Young Adult
chemical_list: D002118:Calcium
keywords: calcium; not in the title: QTc; pediatric reference intervals