ABSTRACT
Introduction The monogenic hypercholesterolaemias account for the most severe elevations of serum low-density lipoprotein cholesterol (LDL-C) and some of the highest-risk situations for atheromatous cardiovascular disease (CVD). Four principal con ditions, termed the ‘cholesterol quartet’ by Goldstein and Brown |1| account for most cases. These are familial hypercholesterolaemia (FH), familial defective apolipoprotein B (FDB), phytosterolaemia (sitosterolaemia) and autosomal recessive hyper cholesterolaemia (ARH). Three of these (FH, FDB and ARH) have defective low-density lipoprotein (LDL) removal by the LDL receptor (LDLR) as their final common pathway leading to hypercholesterolaemia but each has a different under lying genetic defect.
