The FECH gene gives your body instructions for the last step of making heme, an essential part of hemoglobin that helps red blood cells carry oxygen. This gene helps your body keep a light sensitive chemical from building up. When the gene does not work well, that chemical can collect and cause erythropoietic protoporphyria, with burning pain, tingling, or swelling after sunlight and, in some people, liver or gallbladder problems. Inheritance can be complex because a low activity FECH version may add to the effect of another variant.
What is a gene?
A gene is a stretch of DNA that gives your cells instructions for making molecules or directing activities in the body. Some genes carry the code for proteins, which do much of the cell’s work. Other genes mainly regulate when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body develops and works, and they can influence how you respond to food, stress, and medications. For a more detailed look at this topic, you can find more in the LearnHub.
Overview
FECHGene function
What if the gene works
The FECH gene helps your body make heme, a substance used in hemoglobin to carry oxygen in red blood cells. Its protein adds iron at the final step of heme production.
Risk
What if the gene does not work
Variants in the FECH gene can reduce ferrochelatase activity, causing erythropoietic protoporphyria. People often develop painful sensitivity to sunlight, and some may have liver problems. Milder and more severe variants can influence when symptoms start and how strong they are.
Treatment
What does that mean for your treatment
For people with a pathogenic variant in the FECH gene, guidelines include afamelanotide as a disease-specific option that can improve tolerance to sunlight. Management may also include treatment for liver complications when present, but drug choice is guided by symptoms and organ involvement rather than the exact FECH variant.
Conditions associated with FECH
Gene function
What if the gene works
Your body uses the FECH gene to make heme, an iron containing part used in hemoglobin and many other proteins. This matters every day because heme helps blood carry oxygen and helps cells produce energy. Understanding how the FECH gene works helps show how your cells support breathing, movement, and routine organ function.
The FECH gene directs the last step of heme production. Its protein places iron into a heme building block, creating finished heme.
The heme made with help from the FECH gene becomes part of hemoglobin, the protein in red blood cells that carries oxygen. This is a key part of how the FECH gene supports oxygen transport in the body.
Heme is also used in proteins that help cells make energy and handle routine chemical reactions. Because of this, the FECH gene supports everyday cell work in many parts of the body.
What is a variant?
Genetic variants are small differences in a gene’s DNA sequence. They are common and help shape normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many have no noticeable effect and are simply part of natural genetic variation. Sometimes, though, a variant changes how a gene works more substantially and can contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the FECH gene can lower ferrochelatase activity by reducing how much protein is made or by producing an unstable or shortened protein. This is the main molecular change behind variants in the FECH gene in erythropoietic protoporphyria, where a light-sensitive heme building block can collect in developing red blood cells and sometimes the liver. Some variants have a milder low-expression effect, while more disruptive loss-of-function variants leave less activity and may be linked to earlier or noticeable symptoms.
How variants are linked to conditions
Pathogenic variants in the FECH gene cause erythropoietic protoporphyria, a condition with painful reactions to sunlight or bright indoor light. Variants in the FECH gene linked to erythropoietic protoporphyria often include one pathogenic variant plus a common second variant in the FECH gene. Some people also develop liver or gallbladder problems. More common FECH variants on their own do not confirm this diagnosis.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widely found in the general population. Most do not directly affect health and instead reflect natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when several genes and environmental factors play a role. In some situations, though, one well-characterized variant in a specific gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For FECH, risk is shaped mainly by the gene changes you inherit, especially whether a disease-causing FECH change is paired with a lower-working FECH version. For many living with FECH-related light sensitivity, strong sunlight can quickly trigger symptoms, so risk is usually more about inherited genetics and sun exposure than lifestyle choices.
Inheritance of FECH variants
Inheritance of FECH gene variants is most often autosomal recessive in people with FECH-related erythropoietic protoporphyria. This usually means a child inherits one FECH variant from each parent, often one more disruptive variant plus a common low-expression FECH variant from the other parent. When both parents carry a relevant FECH change, each pregnancy has a 25% chance of an affected child, a 50% chance of a child who carries one change, and a 25% chance of a child who inherits neither combination.
What does my FECH result mean for my family?
For FECH, family implications usually fit a recessive pattern, so brothers and sisters may also have the condition or carry a FECH change even if parents do not have symptoms. Parents are often healthy carriers. Children of someone with a FECH-related condition usually carry one FECH change, and the chance of being affected depends on whether the other parent also has a relevant FECH change, including a common low-expression FECH form.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the FECH gene, genetic testing for FECH variants usually uses DNA from a blood sample or cheek swab. A lab reads the FECH gene to look for changes linked to erythropoietic protoporphyria, including the common low expression FECH variant when relevant. Results may be positive, negative, or unclear.
When should I consider getting a genetic test?
Consider FECH genetic testing if someone has repeated severe burning, stinging, or swelling after brief sun exposure, especially starting in childhood, or if a close relative has erythropoietic protoporphyria (EPP). A test can help confirm whether FECH-related EPP is the cause and whether relatives may also carry the change.
A genetic result is only one part of your health story
Genetic results can be informative, yet how much they reveal varies based on the condition and the specific type of variant. Over time, many factors, including lifestyle, environment, age, and medical history, influence how the body functions. In some conditions, especially those affected 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 may also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Small inherited differences can change how the body breaks down a drug, moves it through the body, or responds to it at its target. This helps explain why the same treatment may work well for one person, work less well for another, or cause more side effects in someone who is more sensitive to it.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medications. It studies connections between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medicines, genes can influence how strongly a drug works or how the body handles it. This information can support treatment decisions that are more informed and more individualized. More on this topic is available in the LearnHub.
Drugs influenced by the FECH gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication response. Questions about side effects, new symptoms, or any medicine changes are best discussed with your doctor.
History
Doctors had recognized erythropoietic protoporphyria for decades before the FECH gene was identified as its main genetic cause. In the late 1980s and 1990s, researchers mapped the condition to chromosome 18 and then linked many cases to variants in the FECH gene, helping explain why symptoms often run in families. From these first observations, research expanded steadily. Scientists later showed that many affected people carry one FECH gene variant together with a common low-expression version of the gene on the other copy, which clarified why inheritance can look less straightforward than expected. This work made FECH an important part of the modern story of porphyria genetics.