type 2 hypercholesterolemia occubrs due to

Type II A(Primary familial hypercholesterolemia)There is elevation of LDL. Patients seldom survivethe second decade of life due to ischemic headisease (Table 25.4). The cause is the LDL receptordefect. Receptor deficiency in liver and peripheraltissues will result in the elevation of LDL levels inplasma, leading to hypercholesterolemia. The LDLreceptor defect may be due to the following reasons:1. LDL receptor deficiency.2. Defective binding of B-100 to the receptor. Asubstitution of glutamine for arginine at 3500thamino acid results in poor binding to LDLreceptors. This defect is known as B-3500 orfamilial defective apo-B.3. The receptor-ldl complex is not internalized.Secondary type II hyperlipoproteinemia is seenin hypothyroidism, diabetes mellitus, nephroticsyndrome and cholestasisRef: DM Vasudevan - Textbook of Biochemistry, 6th edition, page no: 300