TY - JOUR
T1 - A lifetime of hypercalcemia and hypercalciuria, finally explained
AU - Jacobs, Thomas P.
AU - Kaufman, Martin
AU - Jones, Glenville
AU - Kumar, Rajiv
AU - Schlingmann, Karl Peter
AU - Shapses, Sue
AU - Bilezikian, John P.
PY - 2014/3
Y1 - 2014/3
N2 - Context: Hypercalcemia, hypercalciuria, and recurrent nephrolithiasis are all common clinical problems. This case report illustrates a newly described but possibly not uncommon cause of this presenting complex. Objective: We report on a patient studied for over 30 years, with the diagnosis finally made with modern biochemical and genetic tools. Design and Setting: This study consists of a case report and review of literature conducted in a University Referral Center. Patient and Intervention: A single patient with hypercalcemia, hypercalciuria, and recurrent nephrolithiasis was treated with low-calcium diet, low vitamin D intake, prednisone, and ketoconazole. Main Outcome Measure: We measured the patient's clinical and biochemical response to interventions above. Results: Calcium absorption measured by dual isotope absorptiometry was elevated at 37.4%. Serum levels of 24,25-dihydroxyvitamin D were very low, as measured in two laboratories (0.62 ng/mL [normal, 3.49 ± 1.57], and 0.18 mg/mL). Genetic analysis of CYP24A1 revealed homozygous mutation E143del previously described. The patient's serum calcium and renal function improved markedly on treatment with ketoconazole but not with prednisone. Conclusions: Chronic hypercalcemia, hypercalciuria, and/or nephrolithiasis may be caused by mutations in CYP24A1 causing failure to metabolize 1,25-dihydroxyvitamin D.
AB - Context: Hypercalcemia, hypercalciuria, and recurrent nephrolithiasis are all common clinical problems. This case report illustrates a newly described but possibly not uncommon cause of this presenting complex. Objective: We report on a patient studied for over 30 years, with the diagnosis finally made with modern biochemical and genetic tools. Design and Setting: This study consists of a case report and review of literature conducted in a University Referral Center. Patient and Intervention: A single patient with hypercalcemia, hypercalciuria, and recurrent nephrolithiasis was treated with low-calcium diet, low vitamin D intake, prednisone, and ketoconazole. Main Outcome Measure: We measured the patient's clinical and biochemical response to interventions above. Results: Calcium absorption measured by dual isotope absorptiometry was elevated at 37.4%. Serum levels of 24,25-dihydroxyvitamin D were very low, as measured in two laboratories (0.62 ng/mL [normal, 3.49 ± 1.57], and 0.18 mg/mL). Genetic analysis of CYP24A1 revealed homozygous mutation E143del previously described. The patient's serum calcium and renal function improved markedly on treatment with ketoconazole but not with prednisone. Conclusions: Chronic hypercalcemia, hypercalciuria, and/or nephrolithiasis may be caused by mutations in CYP24A1 causing failure to metabolize 1,25-dihydroxyvitamin D.
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U2 - 10.1210/jc.2013-3802
DO - 10.1210/jc.2013-3802
M3 - Review article
C2 - 24423361
AN - SCOPUS:84895832812
SN - 0021-972X
VL - 99
SP - 708
EP - 712
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 3
ER -