title: Calcium pyrophosphate deposition disease revealing a hypersensitivity to vitamin D.
abstract: OBJECTIVE
  Hypersensitivity to vitamin D (HVD) due to a loss of function mutation of the CYP24A1 gene, which encodes vitamin D catabolizing enzyme was initially described as a cause of acute hypercalcemia in children and chronic renal diseases in adults.
  
  
  METHODS
  We describe the first case of a patient presenting a calcium pyrophosphate deposition disease (CPDD) revealing a HVD.
  
  
  RESULTS
  An abnormality of phospho-calcic metabolism was discovered during the course of an etiological workup for CPDD in a 52-year-old patient. Laboratory tests revealed a blood calcium level at the upper limit of normal range, a markedly low parathormone level, a 25-hydroxyvitamin D level within the upper level of normal, an elevated 1,25-dihydroxyvitamin D level and an elevated urine calcium level. CYP24A1 gene sequencing analysis revealed two mutations in a heterozygous state. The study of the 25-hydroxyvitamin D3: 24,25-dihydroxyvitamin D3ratio, two metabolites of vitamin D confirmed the enzyme deficiency in vivo. Our observation suggests that this disease could correspond to a rare cause of CPDD.
  
  
  CONCLUSIONS
  In cases of CPDD associated with calcium values within the upper limit of normal range (or hypercalcemia) with an abnormally low PTH, one could suggest searching for HVD.
authors.affiliation: Department of Rheumatology, CHU de Caen, avenue Cote de Nacre, 14000 Caen, France. Electronic address: pauline.baudart@live.fr.
authors.forename: Pauline
authors.initials: P
authors.lastname: Baudart
authors.affiliation: Normandy University, 14032 Caen cedex 5, France; EA2608 Estrogène, Reproduction, Cancer (OeReCa), 14032 Caen, France; Department of Genetics, CHU de Caen, 14000 Caen, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Molin
authors.affiliation: Department of Rheumatology, CHU de Caen, avenue Cote de Nacre, 14000 Caen, France.
authors.forename: Johann
authors.initials: J
authors.lastname: Cesini
authors.affiliation: Department of Biomedical and Molecular Sciences, Queen's University, K7L 3N6 Kingston, Ontario, Canada.
authors.forename: Glenville
authors.initials: G
authors.lastname: Jones
authors.affiliation: Department of Biomedical and Molecular Sciences, Queen's University, K7L 3N6 Kingston, Ontario, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Kaufmann
authors.affiliation: Normandy University, 14032 Caen cedex 5, France; Department of Genetics, CHU de Caen, 14000 Caen, France; UNICAEN, COMETE, 14032 Caen, France; Inserm, U 1075 COMETE, 14032 Caen, France.
authors.forename: Marie Laure
authors.initials: ML
authors.lastname: Kottler
authors.affiliation: Department of Rheumatology, CHU de Caen, avenue Cote de Nacre, 14000 Caen, France; Normandy University, 14032 Caen cedex 5, France; UNICAEN, COMETE, 14032 Caen, France; Inserm, U 1075 COMETE, 14032 Caen, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Marcelli
mesh_terms: D002805:Chondrocalcinosis / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000235:genetics*; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D014807:Vitamin D / Q000009:adverse effects*; D065668:Vitamin D3 24-Hydroxylase / Q000172:deficiency* / Q000235:genetics
chemical_list: D014807:Vitamin D; C585549:CYP24A1 protein, human; D065668:Vitamin D3 24-Hydroxylase
keywords: CYP24A1 mutation; Calcium pyrophosphate deposition disease; Hypercalcemia; Hypersensitivity to vitamin D