The TREH gene helps the lining of your small intestine break down trehalose, a sugar found in foods like mushrooms, seaweed, and some processed products. If this gene does not work well, your body may have trouble digesting trehalose, which can lead to bloating, gas, stomach cramps, or diarrhea after eating those foods. Some people with variants in the TREH gene notice clear food related symptoms, while others have few or no symptoms. A TREH result is one part of understanding digestive symptoms, since many stomach and bowel problems have other causes too.
What is a gene?
Genes are stretches of DNA that carry instructions cells use to make molecules or manage activities in the body. Some genes provide the directions for producing proteins, which are the parts of cells that do much of the work. Others mostly help regulate when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body grows and works, and they can influence how you respond to food, stress, and medications. For a fuller explanation of this topic, you can read more in the LearnHub.
Overview
TREHGene function
What if the gene works
The TREH gene helps make trehalase, an enzyme in the small intestine that breaks down trehalose, a sugar found in foods like mushrooms. This helps your body absorb and use that sugar.
Risk
What if the gene does not work
Variants in the TREH gene can reduce trehalase activity, making trehalose harder to digest. This may cause bloating, cramps, gas, or diarrhea after eating foods like mushrooms, with symptoms ranging from mild to more troublesome depending on the variant.
Treatment
What does that mean for your treatment
Pathogenic variants in the TREH gene usually guide diet rather than medication choice. Management centers on avoiding trehalose, especially mushrooms and products with added trehalose, which can help limit symptoms after eating. No TREH gene specific drug treatment is currently established.
Conditions associated with TREH
Gene function
What if the gene works
Digestion depends on enzymes that cut food into small sugars your body can absorb. The TREH gene provides instructions for trehalase, which works mainly in the small intestine. It helps process trehalose, a natural sugar found in foods such as mushrooms and products made with yeast. This is part of the TREH gene's role in carbohydrate digestion.
TREH makes trehalase, an enzyme that splits trehalose, a natural food sugar, into two glucose molecules. This is the key step your body uses to digest trehalose.
Trehalase works on the surface of cells lining the small intestine, where final food breakdown happens. This placement lets glucose be released close to where it can be absorbed.
By turning trehalose into glucose, the TREH gene supports your body's use of this sugar for energy. After foods such as mushrooms or products made with yeast, this helps normal digestion.
What is a variant?
A genetic variant is a small difference in the DNA sequence of a gene. These differences are common and help make up normal human diversity, such as variation in appearance, metabolism, or the way 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 significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the TREH gene can lower the amount of trehalase made, change its shape so it is less stable, or keep it from working properly at the surface of cells lining the small intestine. In this way, TREH gene variants can cause trehalase deficiency by leaving too little enzyme activity to handle trehalose well. Milder variants may leave some activity, while more severe variants can leave very little or none, which can influence how strongly symptoms appear after trehalose containing foods.
How variants are linked to conditions
Pathogenic variants in the TREH gene cause trehalase deficiency, a rare inherited condition that can lead to bloating, gas, stomach cramps, and diarrhea after eating foods that contain trehalose, such as mushrooms. In affected families, finding disease-causing variants in both copies of the TREH gene can confirm the diagnosis. This is different from common variants that may appear on testing but do not by themselves mean a person will have symptoms.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are common throughout the general population. Most do not have a direct effect on health and simply reflect natural variation among people. For many genes, carrying a variant associated with a condition indicates a possible link rather than a confirmed diagnosis, especially when several genes and environmental factors contribute. 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 TREH, risk is mainly set by the gene change itself when someone inherits changes in both copies. Symptoms are more likely or more noticeable after eating foods high in trehalose, especially mushrooms, while avoiding that sugar can help prevent symptoms but does not change the underlying genetic condition.
Inheritance of TREH variants
TREH-related trehalase deficiency is inherited in an autosomal recessive pattern. This means a person usually develops the condition only if they inherit two TREH gene variants, one from each parent. Parents who each carry one TREH gene variant are usually unaffected carriers. With each pregnancy, two carrier parents have a 25% chance of having a child with trehalase deficiency, a 50% chance of having a carrier child, and a 25% chance of having a child who did not inherit either variant.
What does my TREH result mean for my family?
TREH-related trehalase deficiency is usually passed down in a recessive pattern, so close relatives may also carry a changed TREH copy even if they do not have symptoms. Brothers and sisters of someone with a confirmed TREH-related condition may have a higher chance of having the same condition or being carriers. Family members may want to review this information together if a TREH change has been found in the family.
Genetic information
Genetic testing
How you find out about variants
A TREH genetic test uses a blood or saliva sample to read the TREH gene and look for variants. If you want to know how to test for TREH gene variants, the lab compares your DNA with the usual gene sequence and reports whether any clinically relevant changes were found. Results help clarify whether you carry a variant.
When should I consider getting a genetic test?
Consider TREH genetic testing if you have repeated bloating, stomach cramps, gas, or diarrhea after eating mushrooms or other foods with trehalose, especially if this has happened since childhood or runs in your family. Testing can help confirm an inherited problem breaking down this sugar.
A genetic result is only one part of your health story
Genetic findings can be informative, but what they mean for you varies with the condition and the specific variant. How the body functions over the years is also shaped by factors like age, lifestyle, environment, and medical history. For some health conditions, particularly those affected by many genes, genetic information provides context instead of certainty and makes the most sense when viewed with the rest of a person’s care. In other situations, a genetic finding may offer a clear answer. For topics like medication response, genetic results can also help put personal experiences in context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. One person may break down a drug more slowly, while another may process it faster, so the same treatment can feel stronger, weaker, or last a different amount of time. These inherited differences are common and can influence how well a medicine works or how likely someone is to notice side effects. Medication response is also shaped by age, liver and kidney function, other medicines, and overall health.
What is Pharmacogenetics?
Pharmacogenetics is the area of study focused on how genetic differences affect the way people respond to medicines. It examines links between genes and medications to help explain why the same treatment can work differently in different people. For many drugs, genes influence how the body handles a medicine or how strong its effects are. This information can support treatment decisions that are more informed and more tailored to the individual. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the TREH gene
When should I seek medical advice?
There isn't a broadly confirmed role for this gene in how people respond to medicines, so general questions about treatment, side effects, or health changes are best discussed with your doctor.