This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lipoproteins, Subject name: Biochemistry
Tangier's disease is characterized by: 
Select and explain. 
A. Low or absence of HDL, B. Low LDL concentration, C. Raised chylomicrons, D. Deficiency of LPL
A: Low or absence of HDL
Answer: A: Low or absence of HDL 
Explanation: Tangier's disease/ Familial alpha-lipoprotein deficiency/Hypo alpha lipoproteinemia. Defect in ABC-A 1 receptors which helps in giving cholesterol from peripheral tissue to HDL. HDL is not properly formed- HDL | Other lipoproteins are normal. | Apo A1. Cholesterol accumulates in reticulo endothelial system C/F : Peripheral neuropathy, Hepatosplenomegaly Large orange/ yellow tonsils.