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The official name of this gene is “cytochrome P450, family 11, subfamily B, polypeptide 2.”
CYP11B2 is the gene's official symbol. The CYP11B2 gene is also known by other names, listed below.
The CYP11B2 gene provides instructions for making an enzyme called aldosterone synthase (previously known as corticosterone methyloxidase). This enzyme is found in the adrenal glands, which are located on top of the kidneys. Aldosterone synthase is a member of the cytochrome P450 family of enzymes. These enzymes are involved in many processes in the body.
Aldosterone synthase helps produce a hormone called aldosterone. Aldosterone helps control blood pressure by maintaining proper salt and fluid levels in the body. The aldosterone synthase enzyme is involved in a series of three chemical reactions that produce aldosterone from other (precursor) molecules: the conversion of 11-deoxycorticosterone to corticosterone, the conversion of corticosterone to 18-hydroxycorticosterone, and the conversion of 18-hydroxycorticosterone to aldosterone.
The CYP11B2 gene belongs to a family of genes called CYP (cytochrome P450).
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 30 CYP11B2 gene mutations that cause corticosterone methyloxidase deficiency (also known as aldosterone synthase deficiency) have been identified. These mutations lead to insufficient production of aldosterone, which impairs the kidneys' ability to reabsorb salt (sodium chloride or NaCl) into the blood and release potassium in the urine. As a result, excessive amounts of salt in the form of charged atoms (ions) of sodium (Na+) and chlorine (Cl-) leave the body in the urine, while not enough potassium is released. The resulting imbalance of ions in the body underlies the signs and symptoms of this disorder, which include nausea, vomiting, dehydration, low blood pressure, extreme tiredness (fatigue), and muscle weakness.
The genetic change responsible for familial hyperaldosteronism type I, a disorder that causes high blood pressure (hypertension), fuses the section of the CYP11B2 gene that contains the instructions for making aldosterone synthase to a section of a nearby gene called CYP11B1. The added part of the CYP11B1 gene contains a section called a promoter region, which normally starts the production of the 11-beta-hydroxylase enzyme from the CYP11B1 gene. As part of the fused gene, the CYP11B1 gene's promoter region instead starts the production of aldosterone synthase from the CYP11B2 gene.
The activity of the CYP11B1 gene's promoter region is triggered by a hormone called adrenocorticotropic hormone (ACTH). As a result of the fused gene, aldosterone synthase activity is abnormally responsive to ACTH levels, resulting in excessive amounts of aldosterone being produced. The excessive aldosterone production leads to the hypertension associated with familial hyperaldosteronism type I.
Normal variations (polymorphisms) of the CYP11B2 gene have been associated in some studies with increased risk of cardiovascular problems including hypertension, stroke caused by a lack of blood flow to the brain (ischemic stroke), and a heart rhythm abnormality called atrial fibrillation in people with heart failure. Researchers suggest that differences in blood pressure control resulting from the CYP11B2 gene variations may lead to increased risk of these cardiovascular problems.
Cytogenetic Location: 8q21-q22
Molecular Location on chromosome 8: base pairs 142,910,558 to 142,917,842
The CYP11B2 gene is located on the long (q) arm of chromosome 8 between positions 21 and 22.
More precisely, the CYP11B2 gene is located from base pair 142,910,558 to base pair 142,917,842 on chromosome 8.
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 CYP11B2 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.
adrenal glands ; aldosterone ; atrial ; atrial fibrillation ; cardiovascular ; chloride ; cytochrome P450 ; deficiency ; dehydration ; enzyme ; familial ; fibrillation ; gene ; heart failure ; hormone ; hypertension ; ions ; Na ; NaCl ; potassium ; promoter ; promoter region ; sodium ; sodium chloride
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.