A steady increase in mean serum cholesterol levels has been observed in the Sardinian population over the past three decades, probably related to modifications in the diet such as the introduction of fast food; however, the mean serum values are still lowest compared with the other Italian regions. These data clearly contrast with the presence in our area of five LDL-apheresis centers where, in 20 years of activity, over 16,000 treatments were performed in 60 patients, accounting for 30% of LDL-apheresis-treated patients in Italy. The contrast is even more surprising when one considers that Sardinia has a population of only 1.6 million, i.e., 2.8% of the Italian population. A recessive form of familial hypercholesterolemia, called ARH, was recently discovered and studied in the Sardinian population. It has a prevalence of about 1:38,000- 40,000 for homozygous and double heterozygous subjects, who show clinical features similar to those of classical homozygous familial hypercholesterolemia, a disease characterized by autosomal dominant transmission.