Familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a monogenic disorder of low-density lipoprotein (LDL) metabolism. It is characterised by markedly elevated LDL cholesterol, autosomal dominant inheritance, premature cardiovascular disease and tendon xanthomata. FH is a genetically heterogeneous disorder, but the most common underlying molecular cause is mutation of the LDL receptor gene. The worldwide prevalence of FH is 1: 500. South Africa has three founder populations in which the prevalence of FH may be as high as 1: 70. FH is diagnosed clinically, but the diagnosis can be confirmed by DNA analysis. DNA testing cannot always identify the causative mutation because there are several genes to examine and more than 1 500 different mutations have been identified in the LDL receptor alone. Statins are the treatment of choice for patients with FH. Ezetimibe or cholestyramine can be added if additional LDL lowering is required, or if patients are unable to tolerate high statin doses. (C) SAAFP