Low density lipoprotein receptors (LDLR) are cell surface glycoproteins that regulate LDL cholesterol by scavenging LDL from the blood. LDLR is characterized by a cluster of cysteine-rich class A repeats, EGF-like repeats, the O-linked sμgars domain and six YWTD or class B repeats. Mutations in the LDLR gene cause autosomal dominant disease such as familial hypercholesterolemia (FH) and atherosclerosis.