True regarding familial hypercholesterolemia is:

Familial hypercholesterolemia have defective LDL receptorsMany patients with familial hypercholesterolemia have mutations in the LDLR gene that encodes the LDL receptor protein, which normally removes LDL from the circulation, or apolipoprotein B (ApoB), which is the pa of LDL that binds with the receptor.Patients who have one abnormal copy (are heterozygous) of the LDLR gene may have premature cardiovascular disease at the age of 30 to 40.Having two abnormal copies (being homozygous) may cause severe cardiovascular disease in childhood.Patients may have xanthelasma palpebrarum, yellowish patches consisting of cholesterol deposits above the eyelids.