Explain the workup and the treatable-subset principle to the parents of a regressing child — OSCE

Candidate brief

You are the paediatric registrar seeing this family in clinic today. The task is to explain, in plain language, that their child's loss of previously acquired skills is neurological regression and that it requires a systematic search for a cause - some of which are treatable. You must convey honestly that autism is one possibility but that a number of treatable inborn errors of metabolism must be excluded before that label is accepted, outline the tiered workup and why both parents are tested alongside the child (trio exome), acknowledge the parents' fear and the relative's comment without dismissing them, and agree a clear next-step plan with a named contact and a follow-up appointment. The consultation is ten minutes. [1] [3]

Key teaching points for the candidate

The phrase "loss of previously acquired skills" is the hinge of the consultation. The candidate should distinguish regression from a plateau or a static deficit in plain language, and explain that regression carries the weight of a presumed progressive process - which is why a battery of tests is justified rather than reassuring observation. The candidate should name the principle that governs the workup: a treatable inborn error of metabolism must be excluded before any degenerative label is accepted, because a defined fraction of these disorders respond to a disease-modifying intervention that works best when begun early. [1] [2]

The candidate should explain the tiered workup in family-accessible terms: blood and urine tests that look for chemical imbalances and accumulated substances, a brain scan that shows whether a specific part of the brain is affected, and a genetic test that reads the child's DNA - and, when the child's result points to an inherited change, the parents' DNA too, so the team can tell whether the change was inherited and can plan testing and counselling for the wider family. The candidate should be honest that some causes are not yet treatable, but frame the search positively: the workup exists to find the treatable ones, and even an untreatable answer brings accurate counselling, prognosis, and family planning. [2] [3]

Communication tasks

The candidate should break the news in plain language and pace the information to the parents' readiness, acknowledging their fear and the relative's comment about autism without either agreeing prematurely or dismissing it. The candidate should explain what regression is and why a search for a cause is justified, describe the workup in terms the family can act on, and give an honest account of the timeline - that some results return within days and others take weeks, and that the team will not leave the family waiting without contact. The candidate should offer a written summary, a named coordinator or contact, and a follow-up appointment, and should check understanding before closing - asking the parents to say back what will happen next, so that the plan is shared rather than imposed. [1] [3]