Familial hypercholesterolaemia — SCE Endocrinology MCQ

Correct answer: D — Heterozygous familial hypercholesterolaemia caused by LDLR dysfunction

The best answer is “Heterozygous familial hypercholesterolaemia caused by LDLR dysfunction”. Very high LDL cholesterol, tendon xanthomata and premature first-degree coronary disease satisfy a strong clinical phenotype for heterozygous familial hypercholesterolaemia and should trigger specialist assessment and cascade testing. “Familial chylomicronaemia due to LPL-pathway dysfunction” is less appropriate because chylomicronaemia primarily produces extreme triglyceride elevation and pancreatitis “Isolated dyslipidaemia caused by hypothyroidism” is less appropriate because secondary hypothyroidism has been excluded and does not best explain this inherited xanthoma pedigree “Familial combined hyperlipidaemia without monogenic FH” is less appropriate because familial combined hyperlipidaemia can cause premature disease but tendon xanthomata strongly favour FH “Sitosterolaemia as the presumptive diagnosis without sterol testing” is less appropriate because sitosterolaemia is a rare mimic requiring specific biochemical or genetic evidence rather than being the presumptive diagnosis

Reference: NICE CG71: Familial hypercholesterolaemia — identification and management. https://www.nice.org.uk/guidance/cg71/chapter/Recommendations