A protein named ABC1 (ATP Binding Cassette 1) or CERP (Cholesterol Efflux Regulatory Protein) is able to orient cellular cholesterol towards the cell surface and to facilitate its transfer towards the core of HDL (see hypoalphalipopproteinemias). Tangier disease is recessively inherited, which means that both parental chromosomes should carry a mutation of the ABC1 gene. Disease onset is in childhood manifesting with corneal opacities and tonsil enlargement, which take a particular orange-yellow color, due to cholesterol deposition. Atherosclerosis and cholesterol accumulation within the rectal (end of the large intestine) mucosa are present. Liver and spleen are enlarged, neurologic symptoms are reported. The disseminated cholesterol accumulation in tissues contrasts with the absence of HDL and apo A1 in plasma. The identification of a mutation on the ABC1 gene identifies formally the cause of the disease. About one to two dozen cases of Tangier disease have been described worldwide.
Last update: September 2000