A case of hypercalcemia Indications for 1,25-dihydroxyvitamin D prescription.
Circulating vitamin D is found in various forms: 25-hydroxyvitamin D or calcidiol, majority circulating form, is a "pro-hormon" which will be converted to 1,25-dihydroxyvitamin D or calcitriol, hormone corresponding to vitamin D active form. While determination of 25-hydroxyvitamin D serum levels reflects vitamin D status of patients, determination of 1,25-dihydroxyvitamin D serum level is only indicated in rare cases of suspected hypersensitivity vitamin D in children or of sarcoidosis in adults. There are too many confusion between these two vitamin forms, resulting in inappropriate prescription of 1,25-dihydroxyvitamin D. Here, we describe a case of hypersensitivity to vitamin D by mutation of CYP24A1. We propose to review the interest of 1,25-dihydroxyvitamin D assay in different pathologies, to describe the assay techniques and remind the good prescribing practices of this parameter.
Laboratoire de biochimie, Unité d'hormonologie et de RIA, CHU Hôtel-dieu, Nantes, France.
Damasie
D
Malandain
Clinique médicale pédiatrique, Hôpital mère-enfant, CHU Hôtel-dieu, Nantes, France.
Gwenaëlle
G
Roussey
Laboratoire de biochimie, Unité d'hormonologie et de RIA, CHU Hôtel-dieu, Nantes, France.
Anne-Gaelle
AG
Leloupp
Laboratoire de biochimie, Unité d'hormonologie et de RIA, CHU Hôtel-dieu, Nantes, France.
Nolwenn
N
Graveline
Laboratoire de biochimie, Unité d'hormonologie et de RIA, CHU Hôtel-dieu, Nantes, France.
Damien
D
Masson
Laboratoire de biochimie, Unité d'hormonologie et de RIA, CHU Hôtel-dieu, Nantes, France.
Kalyane
K
Bach-Ngohou
D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000175:diagnosis* / Q000235:genetics*; D007223:Infant; D009154:Mutation; D009397:Nephrocalcinosis / Q000209:etiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000378:metabolism; D065668:Vitamin D3 24-Hydroxylase / Q000235:genetics*
D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C585549:CYP24A1 protein, human; D065668:Vitamin D3 24-Hydroxylase
1; 25-dihydroxyvitamin D; hypercalcemia; hypervitaminosis D; idiopathic infantile hypercalcemia