Zeynep Atay1, Abdullah Bereket2, Belma Haliloglu2, Saygin Abali2, Tutku Ozdogan3, Emel Altuncu3, Lucie Canaff4, Tatiane Vilaça5, Betty Y L Wong6, David E C Cole6, Geoffrey N Hendy4, Serap Turan2. 1. Department of Pediatric Endocrinology, Marmara University, Pendik, Istanbul 34899, Turkey. Electronic address: atay.zeynep@yahoo.com. 2. Department of Pediatric Endocrinology, Marmara University, Pendik, Istanbul 34899, Turkey. 3. Department of Neonatology, Marmara University, Pendik, Istanbul 34899, Turkey. 4. Department of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec H3A 0G4, Canada; Calcium Research Laboratory and Hormones and Cancer Research Unit, Royal Victoria Hospital, Montreal, Quebec H3A 1A1, Canada. 5. Department of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec H3A 0G4, Canada; Department of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec H3A 0G4, Canada. 6. Departments of Laboratory Medicine and Pathobiology, Medicine, and Genetics, University of Toronto, Toronto, Ontario M5G IL5, Canada.
Abstract
BACKGROUND: NSHPT is a life-threatening disorder caused by homozygous inactivating calcium-sensing receptor (CASR) mutations. In some cases, the CaSR allosteric activator, cinacalcet, may reduce serum PTH and calcium levels, but surgery is the treatment of choice. OBJECTIVE: To describe a case of NSHPT unresponsive to cinacalcet. PATIENT AND RESULTS: A 23-day-old girl was admitted with hypercalcemia, hypotonia, bell-shaped chest and respiratory distress. The parents were first-degree cousins once removed. Serum Ca was 4.75 mmol/l (N: 2.10-2.62), P: 0.83 mmol/l (1.55-2.64), PTH: 1096 pg/ml (9-52) and urinary Ca/Cr ratio: 0.5mg/mg. First, calcitonin was given (10 IU/kg × 4/day), and then 2 days later, pamidronate (0.5mg/kg) for 2 days. Doses of cinacalcet were given daily from day 28 of life starting at 30 mg/m2 and increasing to 90 mg/m2 on day 43. On day 33, 6 days after pamidronate, serum Ca levels had fallen to 2.5 mmol/l but, thereafter, rose to 5 mmol/l despite the cinacalcet. Total parathyroidectomy was performed at day 45. Hungry bone disease after surgery required daily Ca replacement and calcitriol for 18 days. At 3 months, the girl was mildly hypercalcemic, with no supplementation, and at 6 months, she developed hypocalcemia and has since been maintained on Ca and calcitriol. By CASR mutation analysis, the infant was homozygous and both parents heterozygous for a deletion-frameshift mutation. CONCLUSION: The predicted nonfunctional CaSR is consistent with lack of response to cinacalcet, but total parathyroidectomy was successful. An empiric trial of the drug and/or prompt mutation testing should help minimize the period of unnecessary pharmacotherapy.
BACKGROUND: NSHPT is a life-threatening disorder caused by homozygous inactivating calcium-sensing receptor (CASR) mutations. In some cases, the CaSR allosteric activator, cinacalcet, may reduce serum PTH and calcium levels, but surgery is the treatment of choice. OBJECTIVE: To describe a case of NSHPT unresponsive to cinacalcet. PATIENT AND RESULTS: A 23-day-old girl was admitted with hypercalcemia, hypotonia, bell-shaped chest and respiratory distress. The parents were first-degree cousins once removed. Serum Ca was 4.75 mmol/l (N: 2.10-2.62), P: 0.83 mmol/l (1.55-2.64), PTH: 1096 pg/ml (9-52) and urinary Ca/Cr ratio: 0.5mg/mg. First, calcitonin was given (10 IU/kg × 4/day), and then 2 days later, pamidronate (0.5mg/kg) for 2 days. Doses of cinacalcet were given daily from day 28 of life starting at 30 mg/m2 and increasing to 90 mg/m2 on day 43. On day 33, 6 days after pamidronate, serum Ca levels had fallen to 2.5 mmol/l but, thereafter, rose to 5 mmol/l despite the cinacalcet. Total parathyroidectomy was performed at day 45. Hungry bone disease after surgery required daily Ca replacement and calcitriol for 18 days. At 3 months, the girl was mildly hypercalcemic, with no supplementation, and at 6 months, she developed hypocalcemia and has since been maintained on Ca and calcitriol. By CASR mutation analysis, the infant was homozygous and both parents heterozygous for a deletion-frameshift mutation. CONCLUSION: The predicted nonfunctional CaSR is consistent with lack of response to cinacalcet, but total parathyroidectomy was successful. An empiric trial of the drug and/or prompt mutation testing should help minimize the period of unnecessary pharmacotherapy.
Authors: Katie Leach; Fadil M Hannan; Tracy M Josephs; Andrew N Keller; Thor C Møller; Donald T Ward; Enikö Kallay; Rebecca S Mason; Rajesh V Thakker; Daniela Riccardi; Arthur D Conigrave; Hans Bräuner-Osborne Journal: Pharmacol Rev Date: 2020-07 Impact factor: 25.468