Tangier diseaseTangier disease (familial alpha-lipoprotein deficiency) is an inherited defect of cholesterol transport resulting in markedly decreased levels of blood high density lipoprotein (HDL) cholesterol. The condition is caused by mutations in ABCA1 gene (9q31) which codes for a transmembrane cholesterol transporter. The ABCA1 protein transports cholesterol from cells into the blood stream where it is combined with apolipoprotein A1 to form HDL. Defective ABCA1 results in low levels of blood HDL cholesterol and accumulation of cholesterol in cells.
The condition follows the autosomal recessive pattern of inheritance and affect males and females equally. Enlarged bright-yellow tonsils are often the first manifestation of the disease. Cholesterol also accumulates in spleen, liver, kidneys, bone marrow, lymph nodes, skin, and cornea. Neuropathy resulting from cholesterol deposits in Schwann cells and Remak cells is common. The risk of atherosclerosis is markedly increased.
The condition is named after Tangier Island (Virginia) where it was first described.