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APOA1

APOA1

Reviewed November 2012

What is the official name of the APOA1 gene?

The official name of this gene is “apolipoprotein A-I.”

APOA1 is the gene's official symbol. The APOA1 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 APOA1 gene?

The APOA1 gene provides instructions for making a protein called apolipoprotein A-I (apoA-I). ApoA-I is a component of high-density lipoprotein (HDL). HDL is a molecule that transports cholesterol and certain fats called phospholipids through the bloodstream from the body's tissues to the liver. Once in the liver, cholesterol and phospholipids are redistributed to other tissues or removed from the body.

ApoA-I attaches to cell membranes and promotes the movement of cholesterol and phospholipids from inside the cell to the outer surface. Once outside the cell, these substances combine with apoA-I to form HDL. ApoA-I also triggers a reaction called cholesterol esterification that converts cholesterol to a form that can be fully integrated into HDL and transported through the bloodstream.

HDL is often referred to as "good cholesterol" because high levels of this substance reduce the chances of developing heart and blood vessel (cardiovascular) disease. The process of removing excess cholesterol from cells is extremely important for balancing cholesterol levels and maintaining cardiovascular health.

How are changes in the APOA1 gene related to health conditions?

familial HDL deficiency - caused by mutations in the APOA1 gene

Mutations in the APOA1 gene cause familial HDL deficiency, an inherited condition characterized by low levels of HDL in the blood and an elevated risk for early-onset cardiovascular disease, which often occurs before age 50. These mutations lead to an altered apoA-I protein. Some versions of the altered protein are less able to promote the removal of cholesterol and phospholipids from cells, which decreases the amount of these substances available to form HDL. Other versions of the altered protein are less able to stimulate cholesterol esterification, which means cholesterol cannot be integrated into HDL particles. Both types of mutation result in low HDL levels. A shortage (deficiency) of HDL is believed to increase the risk of cardiovascular disease.

other disorders - caused by mutations in the APOA1 gene

Mutations in the APOA1 gene can also cause a condition called familial visceral amyloidosis, which is characterized by an abnormal accumulation of proteins (amyloidosis) in internal organs (viscera). The mutations that cause this condition alter the apoA-I protein. Abnormal apoA-I proteins stick together to form amyloid deposits that impair the function of the affected organs. The liver, kidneys, and heart are commonly affected by amyloidosis. Depending on the organs involved, the signs and symptoms of the condition vary. Affected individuals can have an enlarged liver (hepatomegaly), chronic kidney disease, or a form of heart disease called cardiomyopathy. However, in some people, the condition is very mild and causes no apparent signs or symptoms.

Where is the APOA1 gene located?

Cytogenetic Location: 11q23-q24

Molecular Location on chromosome 11: base pairs 116,835,750 to 116,837,621

The APOA1 gene is located on the long (q) arm of chromosome 11 between positions 23 and 24.

The APOA1 gene is located on the long (q) arm of chromosome 11 between positions 23 and 24.

More precisely, the APOA1 gene is located from base pair 116,835,750 to base pair 116,837,621 on chromosome 11.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about APOA1?

You and your healthcare professional may find the following resources about APOA1 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 APOA1 gene or gene products?

  • APOA1_HUMAN
  • apoA-I
  • apo-AI

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 APOA1?

amyloid ; amyloidosis ; apolipoprotein ; apolipoprotein A-I ; cardiomyopathy ; cardiovascular ; cell ; cholesterol ; chronic ; deficiency ; familial ; gene ; HDL ; kidney ; lipoprotein ; molecule ; mutation ; phospholipids ; protein ; viscera

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (9 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.

 
Reviewed: November 2012
Published: July 7, 2014