Defective ABCA1 causes TGD

In an ATP-dependent reaction, ATP-binding cassette sub-family A member 1 (ABCA1) mediates the movement of intracellular cholesterol to the extracellular face of the plasma membrane. Cholesterol associated with cytosolic vesicles is a substrate for this reaction. Under physiologocal conditions, the active form of ABCA1 is post-translationally modified (palmitoylated and phosphorylated), predominantly a tetramer and is associated with apolipoprotein A-I (APOA1). Defects in ABCA1 can cause Tangier disease (TGD; MIM:205400 aka high density lipoprotein deficiency type 1), an autosomal recessive disorder characterised by significantly reduced levels of plasma high density lipoproteins (HDL) resulting in tissue accumulation of cholesterol esters. Low HDL levels are among the most common biochemical abnormalities observed in coronary heart disease (CHD) patients.

Summary from Reactome (R-HSA-5682113), read 2026-09-23.