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The official name of this gene is “ATP-binding cassette, sub-family C (CFTR/MRP), member 9.”
ABCC9 is the gene's official symbol. The ABCC9 gene is also known by other names, listed below.
The ABCC9 gene provides instructions for making the sulfonylurea receptor 2 (SUR2) protein. This protein forms one part (subunit) of a channel that transports charged atoms of potassium (potassium ions) across cell membranes. Each of these channels consists of eight subunits: four SUR2 proteins and four proteins produced from either the KCNJ8 or KCNJ11 gene. The SUR2 subunits regulate the activity of the channel, determining whether it is open or closed.
Channels made with the SUR2 protein are known as ATP-sensitive potassium (K-ATP) channels. The channels open and close in response to the amount of ATP, the cell's main energy source, inside the cell. The resulting transport of potassium ions is part of a complex network of signals that relay chemical messages into and out of cells.
Although K-ATP channels are present in cells and tissues throughout the body, the highest levels of SUR2-containing channels are found in skeletal and heart (cardiac) muscle. These channels indirectly help regulate the concentration of calcium ions in cells. This regulation is essential for normal heart function. The function of these channels in other tissues is unclear.
The ABCC9 gene belongs to a family of genes called ABC (ATP-binding cassette transporters).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.
At least 14 mutations in the ABCC9 gene have been found to cause Cantú syndrome, a rare condition characterized by excess hair growth (hypertrichosis), a distinctive facial appearance, and heart defects. Each of the mutations changes a single protein building block (amino acid) in the SUR2 protein. These changes likely alter the structure of the protein and its ability to regulate the activity of K-ATP channels. Studies suggest that the abnormal channels are open when they should be closed. However, it is unknown how this problem with potassium channel function leads to excess hair growth, heart defects, and the other features of Cantú syndrome.
At least two mutations in the ABCC9 gene have been identified in people with dilated cardiomyopathy, a form of heart disease that enlarges and weakens the cardiac muscle, preventing the heart from pumping blood efficiently. Signs and symptoms of this condition can include an irregular heartbeat (arrhythmia), shortness of breath, extreme tiredness (fatigue), and swelling of the legs and feet. Research suggests that each mutation changes the structure of the SUR2 protein and disrupts the regulation of the K-ATP channel. Although K-ATP channels appear to play an important role in cardiac muscle, little is known about how malfunctioning channels are related to dilated cardiomyopathy.
Cytogenetic Location: 12p12.1
Molecular Location on chromosome 12: base pairs 21,797,388 to 21,941,862
The ABCC9 gene is located on the short (p) arm of chromosome 12 at position 12.1.
More precisely, the ABCC9 gene is located from base pair 21,797,388 to base pair 21,941,862 on chromosome 12.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about ABCC9 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
amino acid ; arrhythmia ; ATP ; calcium ; cardiac ; cardiomyopathy ; cell ; channel ; dilated ; familial ; gene ; hypertrichosis ; ions ; mutation ; potassium ; protein ; receptor ; subunit ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.