The disease phenotype

Familial hypercholesterolemia (1) (McKusick
144400) occurs in about 1 in 500 persons in the
heterozygous state. In the rare homozygous
state (1 in 106) it is a devastating disease usually
leading to death during the first or second decade
of life. The heterozygous form is characterized
by early signs of atherosclerosis (2). The
number of functional LDL receptors per cell is
decreased by about 50% (3). Deposits of
cholesterol esters in the tendons, especially the
achilles tendon, and the skin (xanthomas) are
common in heterozygotes (4). A characteristic
sign is lipid deposits in the eye in front of the iris