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The official name of this gene is “cytochrome P450, family 27, subfamily A, polypeptide 1.”
CYP27A1 is the gene's official symbol. The CYP27A1 gene is also known by other names, listed below.
The CYP27A1 gene is a member of the cytochrome P450 gene family. Enzymes produced from the cytochrome P450 genes are involved in the formation and breakdown of various molecules and chemicals within cells. The CYP27A1 gene provides instructions for producing an enzyme called sterol 27-hydroxylase. This enzyme is located in the energy-producing centers of cells (mitochondria), where it is involved in the pathway that breaks down cholesterol to form acids used to digest fats (bile acids). Specifically, sterol 27-hydroxylase breaks down cholesterol to form a bile acid called chenodeoxycholic acid. The formation of bile acids from cholesterol is the body's main pathway for cholesterol removal. Sterol 27-hydroxylase plays a key role in maintaining normal cholesterol levels in the body.
The CYP27A1 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.
More than 50 mutations that cause cerebrotendinous xanthomatosis have been identified in the CYP27A1 gene. Most of these mutations change one protein building block (amino acid) in the sterol 27-hydroxylase enzyme. The most common mutation changes the amino acid arginine to the amino acid cysteine at position 362 in the protein (written as Arg362Cys or R362C). Changes in amino acids typically disrupt the normal function of the protein and impair its ability to break down cholesterol. Other mutations cause no functional enzyme to be made. The reduction or lack of functional sterol 27-hydroxylase enzyme and subsequent accumulation of cholesterol throughout the body, particularly in the brain and tendons, cause the signs and symptoms of cerebrotendinous xanthomatosis.
Cytogenetic Location: 2q33-qter
Molecular Location on chromosome 2: base pairs 219,646,471 to 219,680,015
The CYP27A1 gene is located on the long (q) arm of chromosome 2 between position 33 and the end (terminus) of the arm.
More precisely, the CYP27A1 gene is located from base pair 219,646,471 to base pair 219,680,015 on chromosome 2.
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 CYP27A1 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.
acids ; amino acid ; bile ; cholesterol ; cytochrome P450 ; enzyme ; gene ; mitochondria ; mutation ; protein
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.