ABCA8
Description of abca8
ABCA8 (ATP-binding cassette transporter A8) is a protein that plays a crucial role in cellular cholesterol homeostasis and lipid metabolism. It is primarily expressed in the liver, the main organ responsible for cholesterol metabolism, as well as in other tissues such as the intestines, kidneys, and macrophages.
ABCA8 is involved in the reverse transport of cholesterol from peripheral tissues back to the liver, a process known as reverse cholesterol transport (RCT). In this process, ABCA8 facilitates the efflux of cholesterol from peripheral cells into apolipoprotein (Apo) A-I, which then forms high-density lipoprotein (HDL) particles. HDL particles carry cholesterol back to the liver, where it can be excreted into bile or converted into bile acids, thereby reducing overall cholesterol levels in the body.
Associated Diseases
Mutations in the ABCA8 gene have been linked to several inherited disorders, known as ABCA8 deficiency disorders, which are characterized by impaired reverse cholesterol transport and abnormal lipid metabolism. These disorders include:
- Familial Hypoalphalipoproteinemia (FHA): A rare autosomal recessive disorder characterized by very low levels of HDL cholesterol and ApoA-I. Individuals with FHA present with increased risk of developing severe coronary artery disease (CAD) and peripheral artery disease (PAD) at a young age.
- Tangier Disease: An extremely rare autosomal recessive disorder characterized by near-complete deficiency of HDL cholesterol and ApoA-I. Individuals with Tangier disease have orange-yellow deposits of cholesterol in the tonsils, lymph nodes, liver, spleen, and other tissues. They also have an increased risk of developing CAD, PAD, and neurological complications.
- Fish Eye Disease (FED): A rare autosomal recessive disorder characterized by the accumulation of cholesterol and phospholipids in the cornea, leading to corneal opacity and visual impairment. Individuals with FED may also have low levels of HDL cholesterol and ApoA-I.
Did you Know ?
Approximately 1 in 500 to 1 in 1,000 individuals of European descent carry a mutation in the ABCA8 gene. This makes ABCA8 deficiency disorders relatively common genetic conditions.
