Novel stop mutation causing familial hypercholesterolemia in a Costa Rican family.

Combined heteroduplex single-strand conformation polymorphism (HEX-SSCP) analysis of the promoter and coding region of the low density lipoprotein receptor (LDLR) gene revealed a novel C to T mutation at nucleotide position 2056 in a Costa Rican patient with heterozygous familial hypercholesterolemia (FH). This nonsense mutation, Q665X, results in a termination codon in the epidermal growth factor (EGF) precursor homology domain of the mature LDLR.