An LDL cholesterol above 4.9 mmol/L in an untreated adult, tendon xanthomata, or a first-degree relative with premature coronary disease should each trigger the same second step: cascade testing. Each first-degree relative of an index case has a one in two chance of carrying the variant, which makes this the highest-yield testing available in cardiology — far higher than any population screen.
It is also the step most often lost. The index patient is started on a statin, the consultation ends, and nobody writes to the family. So do it at the same visit: list the first-degree relatives by name in the notes, give the patient a letter they can hand over, and state explicitly that children should be tested too — treatment in childhood is what prevents the first event, and waiting until adulthood forfeits the years that matter most.
Where genetic testing is unavailable or unaffordable, a fasting lipid profile in each first-degree relative captures most of the benefit. The barrier is almost never the test.
- List first-degree relatives by name in the notes at the index consultation
- Give the patient a letter to hand to relatives rather than relying on them to explain
- Include children explicitly; treatment started early is the point
- Where genetic testing is not available, a lipid profile in each relative captures most of the yield
- Record which relatives have been tested, so the next clinician can see the gap
Why it matters
Half of the relatives of an index case carry the variant, and the step that finds them is administrative rather than clinical.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for cardiology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free