Paeds Cases · endocrinology-diabetes-and-growth
Hypocalcaemia and hypoparathyroidism — OSCE
OSCE communication and clinical reasoning station for the parents of a newly diagnosed infant with 22q11.2 deletion syndrome (DiGeorge) presenting with neonatal hypocalcaemia and seizures.
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MRCPCH ClinicalRACP DCE
Prompt
You have 8 minutes with the parents of a 10-day-old infant who was admitted after a brief seizure and found to have severe hypocalcaemia (ionised 0.7 mmol/L). The bloods showed a low PTH and high phosphate. The genetic test has confirmed 22q11.2 deletion syndrome (DiGeorge syndrome). The infant also has a small ventricular septal defect and a cleft palate. Explain the diagnosis, the calcium problem, the treatment plan, and the broader implications, and agree a way forward.
Station brief (candidate)
- Explain the calcium problem in plain language: a small piece of genetic material is missing (a deletion on chromosome 22), and as a result the small glands near the thyroid that normally control calcium (the parathyroid glands) did not form properly, so the baby's calcium dropped and caused the seizure. [8][9]
- Reassure the parents that the seizure was caused by the low calcium, that the calcium is being corrected with treatment, and that seizures from this cause do not mean ongoing epilepsy — once the calcium is managed, the seizure risk falls. [3]
- Explain the treatment: calcium supplements and a special form of vitamin D (calcitriol) that helps the body absorb calcium. These are given by mouth once the baby is stable, and they are taken regularly to keep the calcium at a safe level. [1]
- Introduce the broader diagnosis: the genetic test confirmed 22q11.2 deletion syndrome, also called DiGeorge syndrome. This can affect several parts of the body — the calcium glands, the heart (the small hole we found), the palate (the cleft), and the immune system. We will arrange the right specialists to assess each of these. [9]
- Explain the monitoring plan: regular blood tests to check the calcium, phosphate, and kidney function, and regular reviews with the paediatric endocrine team. A MedicAlert identifier will be provided so that any doctor who sees the baby knows about the calcium condition. [1]
- Address the future honestly: the calcium condition may be lifelong or it may improve in some children with DiGeorge, so we monitor and adjust. The other features (heart, palate, immune, development) will be assessed by the relevant specialists, and a coordinated plan will be built. [9]
References4ShowHide
- [1]Brandi ML; Bilezikian JP; Shoback D; et al Management of Hypoparathyroidism: Summary Statement and Guidelines. J Clin Endocrinol Metab, 2016.PMID 26943719
- [3]Mannstadt M; Bilezikian JP; Thakker RV; et al Hypoparathyroidism. Nat Rev Dis Primers, 2017.PMID 28857066
- [8]Hsu SC; Levine MA Perinatal calcium metabolism: physiology and pathophysiology. Semin Neonatol, 2004.PMID 15013473
- [9]Wahrmann S; Jokinen E; Pitkänen S; et al Childhood manifestations of 22q11.2 deletion syndrome: A Finnish nationwide register-based cohort study. Acta Paediatr, 2023.PMID 36867048