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Reviewed August 2014
What is the official name of the CYP27B1 gene?
The official name of this gene is “cytochrome P450 family 27 subfamily B member 1.”
CYP27B1 is the gene's official symbol. The CYP27B1 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 CYP27B1 gene?
The CYP27B1 gene provides instructions for making an enzyme called 1-alpha-hydroxylase (1α-hydroxylase). This enzyme carries out the final reaction to convert vitamin D to its active form, 1,25-dihydroxyvitamin D3, also known as calcitriol. Vitamin D can be acquired from foods in the diet or can be made in the body with the help of sunlight. When active, this vitamin is involved in maintaining the proper balance of several minerals in the body, including calcium and phosphate, which are essential for the normal formation of bones and teeth. One of vitamin D's major roles is to control the absorption of calcium and phosphate from the intestines into the bloodstream. Vitamin D is also involved in several process unrelated to bone formation.
In order to carry out the roles of vitamin D, calcitriol attaches (binds) to another protein known as vitamin D receptor (VDR). The resulting calcitriol-VDR complex then binds to particular regions of DNA, known as vitamin D response elements, and regulates the activity of vitamin D-responsive genes. By turning the genes on or off, VDR helps control calcium and phosphate absorption and other processes.
Does the CYP27B1 gene share characteristics with other genes?
The CYP27B1 gene belongs to a family of genes called CYP (cytochrome P450s).
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? in the Handbook.
How are changes in the CYP27B1 gene related to health conditions?
Genetics Home Reference provides additional information about these conditions associated with changes in the CYP27B1 gene:
Where is the CYP27B1 gene located?
Cytogenetic Location: 12q14.1
Molecular Location on chromosome 12: base pairs 57,762,334 to 57,767,193
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The CYP27B1 gene is located on the long (q) arm of chromosome 12 at position 14.1.
More precisely, the CYP27B1 gene is located from base pair 57,762,334 to base pair 57,767,193 on chromosome 12.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about CYP27B1?
You and your healthcare professional may find the following resources about CYP27B1 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 CYP27B1 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 CYP27B1?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (8 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.