Figure 1. Examples of tendon xanthomas seen in patients with familial hypercholesterolaemia. Reprinted with permission from Goldstein JL, Hobbs HH and Brown MS (1995) Familial hypercholesterolaemia. In: Scriver CR, Beaudet AL, Sly WS and Valle D (eds) The Metabolic and Molecular Bases of Inherited Disease, vol. 2, pp. 1981–2030. New York: McGraw-Hill.

Figure 2. Uptake of lipoprotein particles by the low-density lipoprotein receptor. Entry of a receptor–ligand complex into cells occurs at clathrin-coated pits. The complex is subsequently delivered to the low-pH environment of the endosome, where dissociation of the complex takes place. The receptor is then returned to the cell surface in a process called receptor recycling. After Brown MS and Goldstein JL (1986) Science 232: 34–47.

Figure 3. The modular domain organization of the low-density lipoprotein (LDL) receptor. LA, LDL-A ligand-binding modules; EG, epidermal growth factor-like modules; LY, repeats containing a YWTD consensus motif; EGFP, epidermal growth factor precursor. After Springer TA (1998) Journal of Molecular Biology 283: 837–862.

Figure 4. Model illustrating the X-ray structure of the fifth ligand-binding module of the low-density lipoprotein receptor. Side-chains are superimposed on a ribbon trace of the module backbone. Cysteine and additional residues are labelled as reference points. The bound calcium ion is indicated by a blue sphere. Familial hypercholesterolaemia mutations are located at structurally significant residues. Figure generated using the program Insight II. Reprinted with permission from Fass DF, Blacklow S, Kim PS and Berger JM (1997) Nature 388: 691–693.