Caused by mutations in the LDL receptor gene that result in LDL receptor malfunction or absence in cells of the liver and peripheral tissues, leading to elevation of plasma LDL and TC concentrations
Plasma cholesterol concentrations are typically elevated 2fold to 3fold above average in heterozygous subjects and 3 fold to 6 fold in homozygous subjects
Heterozygosits: cholesterol>300mg/dl
LDL-C >250 mg/dl,, TG are not elevated-(1 in 5oo)
Hyperlipidemia is present at birth
Characteristic physical finding:
Tendon xanthoma usually on the Achilles tendons or extensor tendons of the hands
Xanthelasma
premature arcus cornea
Many affected subjects have no physical findings
Premature CAD is common
The age of onset of coronary disease is about 45 years in men and women who are heterozygous for FH