Twelve familial hypercholesterolemia (FH) patients of different ancestries living in South Africa were subjected to mutation analysis of the low-density lipoprotein receptor (LDLR) gene. Nine different mutations were identified in 10 patients. Six of these, including the founder-related mutation C660X identified in two Lebanese patients, have previously been described in other FH patients with compatible genetic backgrounds, and/or in patients originating from countries where admixture is not uncommon. Characterization of an abnormal electrophoresis pattern detected in exon 4 of the LDLR gene by heteroduplex single-strand conformation polymorphism (HEX-SSCP) analysis, revealed a novel G deletion at codon 185 (617delG) which resulted in a downstream stop codon. Two of the new mutations identified resulted in amino acid substitutions and were designated R57C and Q357P.