Lipid disorders and familial hypercholesterolaemia — branching viva

Station opening

Examiner: "Tell me the single concept that frames every child with a raised LDL-C, and why it matters." [1]

Strong candidate (must-hit)

• The concept is the raised LDL-C from birth: a chronic deposit in the arterial wall that drives premature atherosclerosis silently over decades. It matters because the child looks and feels well, so the disease is missed and under-treated, and because the deposit can be prevented — but not easily reversed — by lowering the LDL-C early. That single idea organises the thresholds, the drug ladder and the cascade screen. [1]

Weak candidate

• "A high cholesterol runs in the family." [1]

Branch A — The school-age child with a family history

Examiner: "A well 9-year-old boy has an LDL-C of 6.2 mmol per litre, a normal triglyceride and a father who had an infarct at 48. What is the diagnosis, and what do you do first?" [2]

Strong

• Diagnoses heterozygous familial hypercholesterolaemia: the untreated LDL-C is well above the 5.0 mmol per litre threshold, the triglyceride is normal, and the family history of premature cardiovascular disease is present. First, confirm with a repeat lipid profile and a secondary-cause screen — thyroid-stimulating hormone, renal function and urinalysis, liver function — to exclude hypothyroidism, nephrotic syndrome, cholestasis and a drug, then send genetic testing of LDLR, APOB and PCSK9. [2]

Weak

• "It is probably diet-related — I would give lifestyle advice and recheck in a year." [2]

Branch B — The adolescent with xanthomas

Examiner: "A 14-year-old girl has Achilles-tendon xanthomas, an LDL-C of 14 mmol per litre and exertional chest discomfort. What is the diagnosis, and what is the urgent issue?" [3]

Strong

• Diagnoses homozygous familial hypercholesterolaemia: the LDL-C above 10 mmol per litre, childhood xanthomas and exertional cardiac symptoms mark the severe form. The urgent issue is that her exertional chest discomfort may be premature coronary ischaemia or supravalvar aortic disease, so she needs an electrocardiogram, troponin, urgent echocardiography and paediatric cardiology review now — the lipid problem is chronic, the cardiac event is acute. [3]

Weak

• "She has high cholesterol — I would start a statin and review in clinic." [3]

Branch C — The drug ladder and its safety

Examiner: "The boy in Branch A is confirmed to have FH. Walk me through the drug ladder and the evidence that statins are safe in children." [4]

Strong

• The ladder is lifestyle, then a statin as first-line drug from age 8 to 10 years at the lowest licensed dose and titrated to an LDL-C target ideally below 3.1 mmol per litre, then ezetimibe if the target is not met, then a PCSK9 inhibitor for severe disease. The safety evidence is the PRECURSORY cohort, which showed that a statin started in childhood normalised carotid intima-media thickness, and the twenty-year follow-up, which showed no penalty to growth, puberty or hepatic safety. Homozygous FH adds apheresis, lomitapide and evinacumab. [4] [6]

Weak

• "I would avoid statins in children because of the side effects." [4]

Branch D — The adolescent girl and a future pregnancy

Examiner: "An adolescent girl with FH on a statin asks about a future pregnancy. What do you counsel?" [1]

Strong

• Statins are teratogenic, so reliable contraception is counselled before and during treatment, and the statin is stopped 4 to 6 weeks before a planned pregnancy. Lipid lowering is generally deferred during pregnancy and breastfeeding, because the fetal risk of the drug outweighs the maternal cardiovascular risk of a short treatment gap. The same visit addresses adherence and a structured transition to adult care. [1]

Weak

• "Statins are fine in pregnancy." [1]

Close

Examiner: "Summarise your approach to paediatric familial hypercholesterolaemia in one sentence." [1]

Strong

• "I hold the raised LDL-C from birth in mind: apply the thresholds to flag FH, exclude a secondary cause, confirm genetically, then treat with lifestyle and a statin from age 8 to 10 titrated to a target, adding ezetimibe and a PCSK9 inhibitor as needed, with cascade screening of the family and contraception counselling for the adolescent girl." [1] [2]