Poster Presentation ESA-SRB-APEG-NZSE 2022

Neonatal severe hyperparathyroidism presenting with life-threatening hypercacaemia in a remote hospital treated successfully with medical and surgical management (#452)

Kerri R Rosettenstein 1 , Kristen Neville 1 , Maxwell Hopp 2 , Craig Munns 3 4 , Shihab Hameed 1 5 6 7
  1. Department of Paediatric Endocrinology, Sydney Children's Hospital Network, Sydney, NSW, Australia
  2. Paediatrics, Griffith Base Hospital, Griffith, NSW, Australia
  3. Mayne Academy of Paediatrics, South Brisbane, The University of Queensland, Australia
  4. Department of Endocrinology and Diabetes, Queensland Children's Hospital, South Brisband, QLD, Australia
  5. Division of Women and Children's Health, University of New South Wales, Sydney, NSW, Australia
  6. Department of Paediatric Endocrinology, Sydney Children's Hospital Network, Sydney, NSW, Australia
  7. Division of Women and Children's Health, Sydney University, Sydney, NSW, Australia

62fe34360a312-Image+1+APEG+Abstract.pngNeonatal severe hyperparathyroidism is a rare disorder that presents with potentially life-threatening hypercalcaemia. This case report aims to describe the management complexities of this condition.  A Day 3, full-term male presented to a remote hospital in New South Wales with tachypnoea and hypoxia and was found to be severely hypercalcaemic, with a calcium of 4.32mmol/L (1.89-2.8) and an elevated PTH of 112pmol/L (1.6-6.9). X-rays showed marked osteopaenia, coarsened thoracic cage trabeculae, long bone bowing and rib fractures. With telephone guidance from the paediatric endocrinologist, the general paediatrician commenced IV hyperhydration, frusemide 2mg/kg BD, prednisone 2mg/kg/day and pamidronate 1mg/kg. Following NETS transfer to a tertiary hospital, subcutaneous calcitonin 2u/kg q6hourly and oral cinacalcet (an allosteric calcium sensing receptor activator) 2mg/kg/day were administered as pre-arranged by the ICU team. Calcium levels responded from an initial peak of 5.4mmol/L to 2.1mmol/L on day 4 of treatment, but rebounded to 3.9mmol/L on cessation of IV fluids and reintroduction of calcium-containing feeds. Total parathyroidectomy was performed on day 16 of life. Histopathology showed parathyroid hyperplasia, weight 31-52mg,  similar to adult size. Genetic testing revealed compound heterozygosity for two likely pathogenic variants involving the calcium sensing receptor (c. 190A>G; p.(Asn64Asp) on chr3: 122257085 and c. 101T>C; p.(Leu34Pro) on chr3:122254290). Postoperative hypocalcaemia from hungry bones was anticipated, therefore calcitriol 284ng/kg/day and oral calcium 150mg BD were commenced.  ALP peaked at 2238U/L (120-550). Calcitriol dose peaked at 720ng/kg/day and calcium dose at 360mg/kg/day, but fell after 50 days post-surgery to 296ng/kg/day and 246mg/kg/day, respectively (See image 1). Maintenance dosing of these medications has continued at 20-40ng/kg/day for calcitriol and 5-10mg/kg/day for calcium. The child’s development is normal and there has been clinical resolution of long bone bowing.  This case demonstrates successful emergency medical and surgical management of this life-threatening disease.