the invention relates to extracorporeal methods of analyzing the presence or absence of mutations which cause familial hypercholesterolemia . the inventive methods describe the way in which said mutations can be detected using a dna sample from an individual and comprising the following : chain reaction of the polymerase with primers which are complementary to the low - density lipoprotein receptor gene ; analysis of the amplified product by sequencing ; restriction analysis ; single strand conformation polymorphism techniques ; heteroduplex analysis and analysis of a device on top of a biochip glass support on which oligonucleotide probes are disposed , which can be used to detect the aforementioned mutations in the dna .