The ACADM gene gives your body instructions to break down certain fats for energy, especially during fasting, and if it does not work well, a person may not make enough energy and can develop low blood sugar. This can lead to MCAD deficiency, a condition that may cause vomiting, unusual sleepiness, seizures, or liver problems during illness or long gaps without food. Many people first learn about this gene through newborn screening, because early diagnosis helps families avoid fasting and manage illness safely.
What is a gene?
A gene is a section of DNA that holds instructions your cells can use to make molecules or regulate processes in the body. Some genes carry the instructions for producing proteins, the parts of cells that do the work. Other genes mainly help set when certain processes happen, where they happen, and how strongly they run. Together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. To explore this topic in more detail, you can learn more in the LearnHub.
Overview
ACADMGene function
What if the gene works
The ACADM gene helps your body turn medium-chain fats into energy. This is especially important between meals, during sleep, or when you are sick and need a steady backup fuel supply.
Risk
What if the gene does not work
When the ACADM gene does not work well, MCAD deficiency can cause low blood sugar, vomiting, sleepiness, or liver problems during fasting or illness. Milder and more severe variants can leave less enzyme activity, influencing symptom timing and severity.
Treatment
What does that mean for your treatment
With a pathogenic variant in the ACADM gene, treatment centers on avoiding fasting and giving extra carbohydrates during illness; if eating is not possible, intravenous glucose can help maintain safe blood sugar. There is no ACADM-specific medicine that corrects the variant, and day to day management usually does not change much by the exact variant.
Conditions associated with ACADM
Gene function
What if the gene works
Your body uses the ACADM gene to turn certain fats into usable energy, especially when you have not eaten for a while. Its instructions matter most inside mitochondria, the parts of cells that make energy. Understanding what the ACADM gene does helps explain how the body keeps fuel available between meals and overnight.
The ACADM gene gives cells instructions for a protein that starts breaking down medium-chain fats. This step takes place inside mitochondria, the parts of cells that release energy from food and stored fuel.
When you go several hours without eating, your body can draw on stored fat for fuel. By helping process medium-chain fats, the ACADM gene supports steady energy during sleep, exercise, and time between meals.
This fat processing also helps the liver make ketones (backup fuel molecules). Ketones can supply energy to tissues, including the brain, when glucose from food is not the main fuel source.
What is a variant?
A genetic variant is a slight change in the DNA sequence within a gene. These changes are common and are part of normal human diversity, such as differences 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 situations, though, a variant can more substantially change how a gene functions and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the ACADM gene can change the shape, stability, or amount of the MCAD enzyme, so cells break down medium-chain fats less effectively. This is how ACADM gene variants affect enzyme activity: some variants leave partial activity, while more severe variants can leave very little or none. That functional range can influence whether MCAD deficiency appears earlier or later and how strongly it shows up.
How variants are linked to conditions
Pathogenic variants in both copies of the ACADM gene cause medium-chain acyl-CoA dehydrogenase deficiency, often called MCADD. In families reading about ACADM gene variants and MCADD, this is the main well-established condition linked to the gene. One pathogenic ACADM variant usually indicates carrier status rather than confirming the condition.
A variant is not necessarily a diagnosis
Variants in genes are a routine feature of human biology and are widely seen across the population. Most do not directly affect health and instead reflect normal human diversity. For many genes, a variant associated with a condition points to a possible link, not a definite diagnosis, particularly when several genes and environmental influences play a role. Sometimes, though, one well-characterized variant in a particular gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
The chance of having an ACADM-related condition is mainly set by inheritance: it is higher when both parents carry an ACADM variant, especially in families with a known history. For people living with MCAD deficiency, long periods without food, vomiting, fever, or illness can trigger dangerous low blood sugar and energy problems.
Inheritance of ACADM variants
ACADM-related medium chain acyl CoA dehydrogenase deficiency is inherited in an autosomal recessive pattern. In practical terms, how ACADM gene variants are inherited usually means a child receives one ACADM gene variant from each parent. Parents who each carry one variant are often healthy themselves, and with each pregnancy there is a 25% chance the child inherits both variants, a 50% chance the child is a carrier, and a 25% chance the child inherits neither variant. This pattern affects males and females equally.
What does my ACADM result mean for my family?
For families with an ACADM result linked to medium-chain acyl-CoA dehydrogenase deficiency, close relatives may also carry the same gene change. Brothers and sisters could have the condition or be carriers, and parents are usually carriers. Family members may want to review their own results or family history, especially if there has been low blood sugar, unusual sleepiness during illness, or sudden unexplained illness in infancy.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for ACADM variants works by reading the DNA in the ACADM gene from a blood sample or cheek swab to look for changes. Results can confirm whether you carry a variant, support a diagnosis, or show whether family members may also need testing.
When should I consider getting a genetic test?
Consider ACADM genetic testing if a newborn screen suggests a condition where the body has trouble using certain fats for energy, known medically as medium-chain acyl-CoA dehydrogenase deficiency. It can also help if there are symptoms like low blood sugar during fasting, or if a close family member has an ACADM gene change.
A genetic result is only one part of your health story
A genetic result can provide useful insight, but what it can tell you depends on the condition and the kind of variant involved. How the body functions over time is shaped by many factors, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is best understood alongside other parts of care. In other situations, a genetic result can give a clear answer. In areas such as medication response, genetic results can help put individual experiences into perspective.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to certain medicines. Small differences in genes can change how a drug is processed, how strongly it works, or how sensitive you are to side effects. This helps explain why the same treatment may work well for one person but less well for another, even when they take the same medicine.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can affect a person’s response to medicines. It studies links between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medications, genes can influence how strongly a drug works or how the body handles it. This information can support more informed, more individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the ACADM gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choice or dose. If you have concerns about a medicine, side effects, or how a treatment fits with your overall health, it is best to talk with your doctor.
History
In recent decades, awareness of this gene’s role has grown. Doctors first recognized the condition linked to the ACADM gene in the late 1970s and early 1980s, when some infants and children developed sudden illness during fasting or common infections. As medical science evolved, so did understanding of this gene. In the 1990s, researchers identified changes in the ACADM gene as the cause, which made diagnosis much more precise for affected families. That discovery also helped support expanded newborn screening, first in parts of the United States and Europe and then more widely. Today, the ACADM gene is closely tied to one of the best known success stories in early genetic screening.