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The official name of this gene is “arachidonate 12-lipoxygenase, 12R type.”
ALOX12B is the gene's official symbol. The ALOX12B gene is also known by other names, listed below.
The ALOX12B gene provides instructions for making an enzyme called 12R-LOX. This enzyme is part of a family of enzymes called arachidonate lipoxygenases. Most of these enzymes help add an oxygen molecule to a certain fatty acid called arachidonic acid. The addition of an oxygen molecule to arachidonic acid produces substances called fatty acid hydroperoxides, which can be transformed into a variety of signaling molecules. Specifically, the 12R-LOX enzyme helps add an oxygen molecule to arachidonic acid to make a substance called 12R-hydroperoxyeicosatetraenoic acid (12R-HPETE). 12R-HPETE is later converted to a signaling molecule that is involved in the growth and division (proliferation) and specialization (differentiation) of skin cells.
The 12R-LOX enzyme is thought to play a role in the formation and maintenance of the fat (lipid) membrane of the cells that make up the outermost layer of the skin (the epidermis). The epidermis helps prevent water loss, regulates body temperature, and protects against infection.
The ALOX12B gene belongs to a family of genes called ALOX (arachidonate lipoxygenases).
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 30 mutations in the ALOX12B gene have been found to cause nonbullous congenital ichthyosiform erythroderma (NBCIE). Most of these mutations change single protein building blocks (amino acids) in the 12R-LOX enzyme. Many ALOX12B gene mutations lead to the production of a nonfunctional 12R-LOX enzyme, which impairs the formation of the lipid membrane of the cells within the epidermis. Problems with this protective barrier underlie the skin abnormalities and other features of NBCIE.
Another form of ichthyosis called self-healing collodion baby has been found to be caused by ALOX12B gene mutations. Individuals with this condition are born with a tight, clear sheath covering their skin called a collodion membrane. This membrane is usually shed during the first few weeks of life, and affected infants often show near normal skin within a few months.
Only a few people diagnosed with self-healing collodion baby have been found to have ALOX12B gene mutations; the majority of cases are caused by mutations in other genes.
Cytogenetic Location: 17p13.1
Molecular Location on chromosome 17: base pairs 8,072,635 to 8,087,702
The ALOX12B gene is located on the short (p) arm of chromosome 17 at position 13.1.
More precisely, the ALOX12B gene is located from base pair 8,072,635 to base pair 8,087,702 on chromosome 17.
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 ALOX12B 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 ; congenital ; differentiation ; enzyme ; epidermis ; erythroderma ; gene ; ichthyosiform ; ichthyosis ; infection ; lipid ; molecule ; oxygen ; proliferation ; 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.