Counsel a family on a new X-linked agammaglobulinaemia diagnosis — OSCE

Candidate brief

You have eight minutes to counsel the parents of a nine-month-old boy in whom you suspect X-linked agammaglobulinaemia. The diagnosis is not yet genetically confirmed. Use a structured, honest, empathic approach. [1] [2]

Key teaching and communication objectives

Acknowledge and validate the parents' fear and guilt before delivering information. Explain that the condition is genetic but not anyone's fault, that it affects the part of the immune system that makes antibodies, and that with consistent treatment the prognosis is good. [2] [3]

Explain the next steps in plain language: a functional vaccine response test and genetic testing to confirm the specific diagnosis, because the right treatment depends on confirming the defect rather than acting on a single number alone. Address the online concern honestly: in some babies a low antibody level is a self-limiting maturational phase, but the combination of absent tonsils, absent B cells, and recurrent deep infection in a boy points to a specific genetic condition that does not resolve on its own. [1] [4]

Describe what immunoglobulin replacement involves (regular infusions to replace the antibody his body cannot make), that it is lifelong, and that it is usually well tolerated. Mention the family implications: carrier testing for the mother's female relatives, because each carrier son has a one-in-two chance of being affected. [2] [3]

Close with a shared plan and a clear next appointment, and an offer of written information and contact with a patient-support organisation. [3]