The DGAT1 gene helps cells in the gut and other tissues turn dietary fat into triglycerides, a main form of stored fat. When this gene does not work properly, babies may have trouble absorbing fat, which can lead to severe diarrhea, vomiting, poor weight gain, and low blood protein levels. This gene plays an important role in how the intestine handles fat after a meal. DGAT1 is not a gene that has become widely known in popular culture, but it is important in rare inherited conditions affecting digestion and growth.
What is a gene?
A gene is a stretch of DNA that carries instructions your cells use to make molecules or regulate processes in the body. Some genes provide the directions for producing proteins, which are the parts of cells that do much of the work. Others are mainly involved in controlling 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, or medicines. To go deeper into this topic, you can find more in the LearnHub.
Overview
DGAT1Gene function
What if the gene works
The DGAT1 gene helps cells make fats called triglycerides, the main form of stored fat. This supports fat absorption from food and normal fat storage, especially in the intestine and other tissues.
Risk
What if the gene does not work
More severe variants in the DGAT1 gene can cause early, often severe diarrhea, vomiting, poor weight gain, and low blood protein from trouble absorbing dietary fat. Milder variants may lead to a less severe or later-onset picture.
Treatment
What does that mean for your treatment
People with pathogenic variants in the DGAT1 gene usually benefit from strict restriction of long chain dietary fat, often using very low fat formulas with careful replacement of essential fats and vitamins A, D, E, and K. Special fats called medium chain triglycerides may help because the body handles them differently. No DGAT1-specific drug treatment is currently established.
Conditions associated with DGAT1
Gene function
What if the gene works
Every day, your body turns some fat from food into a form it can package, move, and store. The DGAT1 gene helps with the final step of making triglycerides, a main storage form of fat. This is part of how the DGAT1 gene helps your body handle dietary fat after meals and save energy for later.
The DGAT1 gene helps cells complete the last step of triglyceride production. This turns smaller fat building blocks into a form the body can store and use as fuel later.
In the small intestine, its protein helps package absorbed fat after you eat. This lets dietary fat move from the gut into the bloodstream in a controlled way.
Many cells use DGAT1 activity to place triglycerides into tiny fat droplets for safekeeping. These droplets act like small energy reserves that the body can draw on between meals.
What is a variant?
A genetic variant is a minor change in a gene’s DNA sequence. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, and the way the body reacts to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. At times, though, a variant changes how a gene works more significantly and may contribute to or lead to a genetic condition.
Genetic variants
What if the gene does not work
Variants in the DGAT1 gene can make the enzyme unstable, less active, or completely absent, so cells struggle to turn fatty acids into triglycerides. In practical terms, this explains how DGAT1 gene variants affect fat processing at the cellular level. Milder variants may leave some enzyme activity, while more severe variants, such as variants that truncate the protein, often remove activity almost entirely. When both gene copies are strongly affected, symptoms may begin earlier and be more marked.
How variants are linked to conditions
Rare disease-causing DGAT1 gene variants can cause a form of congenital diarrhea that often begins in infancy, with loss of protein through the gut, poor weight gain, and low blood protein. This condition often appears soon after feeds containing fat begin, and finding two harmful variants in the DGAT1 gene can confirm the diagnosis. People who carry one variant are usually healthy.
A variant is not necessarily a diagnosis
Genetic variants are a common, normal feature of human biology. Most do not directly affect health and simply contribute to natural differences between people. For many genes, having a variant associated with a condition points to a possible link rather than a certain diagnosis, particularly when several genes and environmental influences also play a role. In other situations, though, one well understood variant in a particular gene is enough to confirm the diagnosis.
Are there things that can increase or change my risk?
For DGAT1, risk is mainly shaped by inheritance rather than lifestyle. A child’s chance is higher when both parents carry a changed DGAT1 gene, especially in families with a known history of this condition or where the parents are related by blood; diet or daily habits do not appear to change the chance of having it.
Inheritance of DGAT1 variants
DGAT1-related conditions follow an autosomal recessive pattern of inheritance. This means a child usually needs to inherit two disease-causing variants in the DGAT1 gene, one from each parent, to be affected. Parents who each carry one variant are often unaffected carriers. With each pregnancy, they have a 25% chance of having an affected child, a 50% chance of having a child who is a carrier, and a 25% chance of having a child without either variant. This is how DGAT1 gene variants are inherited in the well-established condition linked to this gene.
What does my DGAT1 result mean for my family?
For families with a disease-causing DGAT1 result, this usually means the condition follows a recessive pattern. Parents are often healthy carriers, brothers and sisters may also be affected or be carriers, and other close relatives may carry the same change without knowing it. This can matter for future pregnancies and for relatives who are planning children.
Genetic information
Genetic testing
How you find out about variants
DGAT1 genetic testing is usually done on a blood sample or cheek swab. A lab reads the DGAT1 gene to look for changes that may explain symptoms such as ongoing diarrhea in infancy and reports whether a variant is found in one or both copies.
When should I consider getting a genetic test?
Genetic testing for the DGAT1 gene may be considered in babies or young children with severe ongoing diarrhea, vomiting, and poor weight gain starting early in life, especially if blood protein is low or symptoms worsen with feeding. It can also help when a sibling or close relative has a confirmed DGAT1-related condition.
A genetic result is only one part of your health story
Genetic results can provide useful insight, but how much they explain varies by the condition and the type of variant involved. Many factors, including age, lifestyle, environment, and medical history, also shape how the body works over time. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best understood together with other parts of care. In other situations, a genetic result can give a clear answer. In areas such as medication response, these results can 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 differences in genes can change how the body absorbs, breaks down, transports, or responds to a drug. This is common and 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 is the study of how differences in genes can shape the way a person responds to medications. It examines connections between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medicines, genes can affect either how strongly a drug works or how the body processes it. This information can support treatment decisions that are more informed and more individualized. If you want to learn more about this topic, you can explore it further in the LearnHub.
Drugs influenced by the DGAT1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices, so questions about side effects, medicine safety, or how well a treatment is working are best discussed with your doctor.
History
The DGAT1 gene entered modern genetics in the late 1990s, when researchers identified it as the gene behind a key step in fat production. From these first observations, research expanded steadily. In the early 2000s, DGAT1 became especially well known in animal genetics after studies linked a variant in cattle to differences in milk fat and milk yield, making it important in dairy breeding. Mouse studies around the same time drew broad scientific interest because animals lacking this gene showed striking changes in body fat and metabolism. These findings helped place the DGAT1 gene at the center of work on nutrition, obesity, and agricultural genetics. Over time, scientists’ understanding of the gene’s importance grew across both medicine and farming.