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The official name of this gene is “holocytochrome c synthase.”
HCCS is the gene's official symbol. The HCCS gene is also known by other names, listed below.
The HCCS gene carries instructions for producing an enzyme called holocytochrome c-type synthase. This enzyme is active in many tissues of the body and is found in the mitochondria, the energy-producing centers within cells.
Within the mitochondria, the holocytochrome c-type synthase enzyme helps produce a molecule called cytochrome c. Specifically, holocytochrome c-type synthase is involved in a reaction that adds an iron-containing molecule called heme to make mature cytochrome c, also called holocytochrome c, from a precursor form called apocytochrome c.
Cytochrome c is involved in a process called oxidative phosphorylation, by which mitochondria generate adenosine triphosphate (ATP), the cell's main energy source. It also plays a role in the self-destruction of cells (apoptosis).
At least three HCCS gene mutations have been identified in individuals with microphthalmia with linear skin defects syndrome. Deletions of genetic material that include the HCCS gene have also been identified in affected individuals. HCCS gene mutations result in a holocytochrome c-type synthase enzyme that cannot perform its function. A deletion of genetic material that includes the HCCS gene prevents the production of the enzyme from that copy of the gene. This loss of functional holocytochrome c-type synthase enzyme can damage cells by impairing their ability to generate energy. In addition, without sufficient holocytochrome c-type synthase enzyme, the damaged cells may not be able to undergo apoptosis. These cells may instead die in a process called necrosis that causes inflammation and damages neighboring cells. During early development this spreading cell damage may lead to the eye and skin abnormalities characteristic of microphthalmia with linear skin defects syndrome.
Cytogenetic Location: Xp22.3
Molecular Location on the X chromosome: base pairs 11,111,285 to 11,123,085
The HCCS gene is located on the short (p) arm of the X chromosome at position 22.3.
More precisely, the HCCS gene is located from base pair 11,111,285 to base pair 11,123,085 on the X chromosome.
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 HCCS 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.
adenosine triphosphate ; apoptosis ; ATP ; cell ; deletion ; enzyme ; gene ; heme ; inflammation ; iron ; mitochondria ; molecule ; necrosis ; oxidative phosphorylation ; phosphorylation ; precursor ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://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.