The SDHC gene helps your cells make energy from food and keep normal growth signals under control. This gene plays an important role in the cell’s energy machinery. If it does not work properly, certain cells may build up abnormal chemical signals that can lead to tumors called paragangliomas, often in the head and neck, and sometimes pheochromocytomas or a few other tumor types. SDHC is mainly known in clinical genetics rather than in popular culture.
What is a gene?
A gene is a section of DNA that holds information your cells use to make molecules or regulate processes in the body. Some genes carry instructions for making proteins, which are the working parts of cells. Other genes mainly help determine when certain processes occur, where they occur, and how strongly they operate. Together, genes influence how the body develops and functions, and they can shape how you respond to food, stress, or medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
SDHCGene function
What if the gene works
The SDHC gene helps mitochondria turn food into usable energy. It is part of complex II, a protein group that supports both the cell’s energy cycle and energy transfer.
Risk
What if the gene does not work
Pathogenic variants in the SDHC gene are linked mainly to paragangliomas, often in the head and neck, and less often to pheochromocytoma or stomach tumors. Effects vary, with milder or more severe variants influencing which tumors develop and when.
Treatment
What does that mean for your treatment
No treatment or drug choice is currently tailored specifically to a pathogenic variant in the SDHC gene. Care usually follows the tumor or condition present rather than the gene itself. SDH-deficient tumors linked to SDHC are being studied as biomarkers and possible drug targets, but this has not yet led to guideline-based SDHC-specific therapy.
Conditions associated with SDHC
Gene function
What if the gene works
Your cells need steady energy every minute, especially in muscles, nerves, and other active tissues. The SDHC gene helps power this process inside mitochondria, the parts of cells that turn food into usable energy. Understanding what the SDHC gene does in the body starts with its role in a key energy-making enzyme.
Inside mitochondria, the SDHC gene helps a protein complex pass electrons along the cell’s energy chain. This step supports the production of ATP, the main energy source your cells use for routine work.
One of its main jobs is to help cells turn succinate into fumarate during the Krebs cycle, a core energy pathway. That lets your body extract more usable energy from food.
The SDHC protein helps position this energy complex in the inner mitochondrial membrane, where these reactions need to happen. Keeping the complex in place helps the energy transfer process run smoothly.
What is a variant?
A genetic variant is a minor change in the DNA sequence of a gene. These changes are common and help account for normal human diversity, such as differences in appearance, metabolism, or how the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some cases, though, a variant can change how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the SDHC gene can change the protein’s shape, stability, or amount, so the cell’s energy complex may not assemble properly or move electrons efficiently. In plain terms, SDHC gene variant effects often range from milder changes that leave some activity intact to more disruptive variants that greatly reduce or stop protein function. This can lead to stronger chemical signaling inside cells and, in some people, may be linked to earlier or more extensive SDHC related tumor development.
How variants are linked to conditions
Pathogenic variants in the SDHC gene cause an inherited paraganglioma-pheochromocytoma syndrome, most often linked to head and neck paragangliomas (usually tumors near nerves and blood vessels). Some people carrying this gene change also develop pheochromocytoma (a similar tumor in an adrenal gland) or gastrointestinal stromal tumors. Not everyone with an SDHC variant develops the same tumors, and age of onset can vary.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are common across the general population. Most do not have a direct effect on health and simply reflect natural human variation. For many genes, carrying a variant associated with a condition suggests a possible link rather than a definitive diagnosis, especially when multiple genes and environmental factors also play a role. In some situations, though, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For SDHC, the main factor affecting risk is whether you carry a disease-causing change in the gene, and family history can also help show how likely related tumors are in a family. There is not yet broadly confirmed evidence that lifestyle or environmental factors clearly raise or lower this risk.
Inheritance of SDHC variants
In hereditary paraganglioma-pheochromocytoma syndrome, SDHC gene variants are usually inherited in an autosomal dominant pattern. This means a person needs one disease-causing variant in the SDHC gene to have the inherited predisposition, and each child of a parent who carries it has a 50% chance of inheriting that same variant. Sons and daughters can inherit it equally, and it can be passed down by either parent. Not everyone who inherits an SDHC gene variant will develop the same health problems.
What does my SDHC result mean for my family?
For the inherited tumor risk linked to the SDHC gene, close relatives such as parents, brothers, sisters, and children may also carry the same gene change, so the result can matter for family members too. SDHC can also be linked to a separate, much rarer condition when both copies of the gene are changed, so family meaning depends on which SDHC-related condition the result is tied to. In that rarer situation, relatives may be healthy carriers.
Genetic information
Genetic testing
How you find out about variants
SDHC genetic testing uses a blood or saliva sample to look for inherited variants in the SDHC gene. In SDHC genetic testing for paraganglioma and related tumors, the lab reads the gene’s DNA code and reports whether a variant is benign, uncertain, or pathogenic.
When should I consider getting a genetic test?
Consider testing the SDHC gene if you have had a paraganglioma or pheochromocytoma, which are rare tumors that can grow near nerves or in the adrenal glands. It may also be worth discussing if these tumors run in your family, or if someone in the family was diagnosed at a younger age or had more than one tumor.
A genetic result is only one part of your health story
A genetic result can provide valuable information, but what it can tell you varies with the condition and the kind of variant involved. Over time, many factors, including lifestyle, environment, age, and medical history, influence how the body functions. For some conditions, especially those shaped by many genes, genetic information offers context rather than certainty and is most useful when considered alongside other parts of care. In other situations, a genetic result can give a clear answer. In areas like medication response, genetic results can also help make sense of individual experiences.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Small differences in DNA can change how the body breaks down a drug, moves it through the bloodstream, or responds to it at its target. This helps explain why the same treatment may work well for one person, have less effect in another, or cause more side effects in someone else. These differences are common and are one part of the larger picture that shapes medication response.
What is Pharmacogenetics?
Pharmacogenetics looks at how differences in genes can affect a person’s response to medications. It examines links between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medicines, genes influence both how the body processes a drug and how strong its effects may be. This information can support more informed, more individualized treatment choices. To explore this subject in greater detail, you can learn more in the LearnHub.
Drugs influenced by the SDHC gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medicine choices or dose changes. For questions about side effects, new symptoms, or how your medicines fit with your overall health, speak with your doctor or pharmacist.
History
Doctors first recognized inherited paraganglioma through family patterns long before the exact genes were known. In 2000 and 2001, studies of these families identified several related genes, including the SDHC gene, as part of the explanation. Building on this early work, scientists uncovered more about the gene’s link to hereditary paraganglioma and, less often, certain gastrointestinal stromal tumors. These findings helped shift cancer genetics toward a broader view that some tumors can arise from changes in cell energy pathways, not only from the better known growth control genes. Over time, descriptions became more precise as genetic testing improved and more families were studied. Today, the SDHC gene is recognized as one part of that important chapter in inherited tumor research.