Cardiology>>>>>Genetics, Lipids And Tumours
Question 2#

You are looking after a 38-year-old man on the ward who was admitted with a STEMI and treated with PCI. His total cholesterol has been found to be 11.8 mmol/L with LDL 7.3 mmol/L, and he has corneal arcus, tendon xanthomata, and a paternal family history of premature cardiovascular disease. 

What is the most likely causative gene?

a. Proprotein convertase subtilisin-kexin type 9 (PCSK9)
b. Low-density lipoprotein receptor (LDLR)
c. Apolipoprotein B-100 (APOB)
d. Sterol 27-hydroxylase (CYP27A1)
e. Low-density lipoprotein receptor adaptor protein 1 (FHCB2/ARH)

Correct Answer is B


The clinical scenario is typical of familial hypercholesterolaemia. Although PCSK9 and APOB are causes, the most common cause is mutations in the low-density lipoprotein receptor. Sterol 27-hydroxylase causes cerebrotendinous xanthomatosis, and the low-density lipoprotein receptor adaptor protein 1 causes recessive hypercholesterolaemia.