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Reviewed August 2012
What is the official name of the APOB gene?
The official name of this gene is “apolipoprotein B (including Ag(x) antigen).”
APOB is the gene's official symbol. The APOB gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the APOB gene?
The APOB gene provides instructions for making two versions of the apolipoprotein B protein, a short version called apolipoprotein B-48 and a longer version known as apolipoprotein B-100. Both of these proteins are components of lipoproteins, which are particles that carry fats and fat-like substances (such as cholesterol) in the blood.
Apolipoprotein B-48 is produced in the intestine, where it is a building block of a type of lipoprotein called a chylomicron. As food is digested after a meal, chylomicrons are formed to carry fat and cholesterol from the intestine into the bloodstream. Chylomicrons are also necessary for the absorption of certain fat-soluble vitamins such as vitamin E and vitamin A.
Apolipoprotein B-100, which is produced in the liver, is a component of several other types of lipoproteins. Specifically, this protein is a building block of very low-density lipoproteins (VLDLs), intermediate-density lipoproteins (IDLs), and low-density lipoproteins (LDLs). These related molecules all transport fats and cholesterol in the bloodstream.
Low-density lipoproteins are the primary carriers of cholesterol in the blood. Apolipoprotein B-100 allows these particles to attach to specific receptors on the surface of cells, particularly in the liver. The receptors transport low-density lipoproteins into the cell, where they are broken down to release cholesterol. The cholesterol is then used by the cell, stored, or removed from the body.
How are changes in the APOB gene related to health conditions?
Where is the APOB gene located?
Cytogenetic Location: 2p24-p23
Molecular Location on chromosome 2: base pairs 21,224,300 to 21,266,944
The APOB gene is located on the short (p) arm of chromosome 2 between positions 24 and 23.
More precisely, the APOB gene is located from base pair 21,224,300 to base pair 21,266,944 on chromosome 2.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about APOB?
You and your healthcare professional may find the following resources about APOB helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the APOB gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding APOB?
amino acid ; apolipoprotein ; arteries ; cell ; cholesterol ; chylomicrons ; coronary ; critical region ; familial ; gene ; heart attack ; intestine ; lipoprotein ; low-density lipoproteins ; mutation ; protein ; soluble ; vitamins
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (11 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.