Hypocalcaemia and hypoparathyroidism — OSCE

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]

Role-player notes

You are the parents of a 10-day-old baby who was admitted after a seizure at home. You are frightened and exhausted. You have been told the baby has a low calcium and "a genetic condition" but you do not understand what either means. You are terrified that the seizure means brain damage or epilepsy. You become anxious if the doctor uses jargon ("parathyroid", "deletion", "22q11.2") without explaining it. You want to know: will my baby have more seizures? Is this permanent? What does the genetic condition mean for my baby's future? You engage well when the doctor explains the calcium problem clearly, reassures you that the seizure was from the calcium and is treatable, introduces the genetic diagnosis honestly but gently, and gives you a concrete plan with named specialists. You ask whether you or your other children should be tested. [9]

Expected candidate performance

1. Opening: "The seizure your baby had was caused by a low level of calcium in the blood. We have now treated it, and the calcium is coming back up. The reason the calcium was low is that a small piece of genetic information is missing, and as a result the tiny glands that normally control calcium did not form properly. The good news is that we can replace what the glands would normally make, and keep the calcium safe with medication." [3]
2. Explaining the diagnosis: "The genetic test confirmed a condition called 22q11.2 deletion syndrome, or DiGeorge syndrome. It is caused by a small missing piece on chromosome 22, and it can affect several parts of the body. In your baby, it has affected the calcium glands, caused a small hole in the heart, and a cleft in the palate. These are all things we can assess and manage. The calcium part is what caused the seizure, and it is fully treatable." [9]
3. Treatment plan: "Your baby will take calcium and a special vitamin D (called calcitriol) by mouth, several times a day. These keep the calcium at a safe level so the seizure risk falls. We will check the blood regularly and adjust the doses. Once the calcium is stable and the baby is feeding well, we can go home with a clear plan." [1]
4. Monitoring and safety: "Regular blood tests and reviews with the endocrine team. A MedicAlert bracelet or identifier so any doctor who sees your baby knows about the calcium condition. If your baby is unwell or not feeding, contact us early, because illness can change the calcium quickly. We will also arrange the heart, palate, and immune assessments with the relevant specialists." [1][9]
5. Prognosis and the future: "The calcium condition may be lifelong, but in some children with DiGeorge it improves over time, so we monitor rather than assume. The seizure was from the low calcium, not from epilepsy, so the risk of further seizures falls as we manage the calcium. Your baby's development, growth, and quality of life are expected to be good with the right support. We can arrange genetic counselling for you and your family, including testing if appropriate." [8][9]

Marking domains

• Clinical reasoning: correctly frames the diagnosis as DiGeorge with hypoparathyroidism, explains the calcium-PTH link, and identifies the associated features (cardiac, palatal, immune). [9]
• Communication: speaks to the parents in plain language, addresses their fear about seizures and brain damage, and reassures that the condition is treatable. [3]
• Treatment plan: calcium and calcitriol, regular monitoring, MedicAlert, and the sick-day safety plan. [1]
• Shared decision-making and safety-netting: honest prognosis, multidisciplinary coordination, and genetic counselling for the family. [9]

Common fails

• Using jargon ("parathyroid", "22q11.2 deletion", "calcitriol", "PTH") without translation. [9]
• Not addressing the parents' fear that the seizure means brain damage or epilepsy. [3]
• Vague safety advice ("give calcium") without specifying the dose, frequency, sick-day plan, and MedicAlert. [1]
• Not introducing the broader DiGeorge diagnosis or arranging the cardiac, palatal, and immune assessments. [9]
• Not offering genetic counselling or family testing. [9]
• Giving a falsely reassuring or falsely pessimistic prognosis without acknowledging the uncertainty about whether the hypoparathyroidism is transient or permanent. [8]