The SARDH gene helps your body break down sarcosine, a natural substance made during normal protein use. If this gene does not work properly, sarcosine can build up in the blood and urine, a finding called sarcosinemia. Many people with variants in the SARDH gene stay well, though a few have been reported with learning or development differences and effects can vary. Understanding this gene can help clarify why a lab test shows high sarcosine.
What is a gene?
Genes are stretches of DNA that give your cells instructions for making molecules or guiding activities in the body. Some genes provide the code to produce proteins, which do much of the cell’s work. Others mainly regulate when certain processes happen, where they take place, and how active they are. Taken together, genes affect how the body develops and works, and they can shape how you respond to food, stress, and medications. You can find more on this topic in the LearnHub.
Overview
SARDHGene function
What if the gene works
The SARDH gene helps your cells break down sarcosine, a natural byproduct of choline and glycine metabolism. Its protein works in mitochondria (the parts of cells that produce energy) and supports normal amino acid balance.
Risk
What if the gene does not work
Variants in the SARDH gene can reduce sarcosine breakdown, causing sarcosinemia. Many people have no clear symptoms, while some may have mild developmental or neurologic features. Milder and more severe variants can affect how much enzyme activity remains.
Treatment
What does that mean for your treatment
No SARDH-specific treatment or drug choice is currently established for pathogenic variants in the SARDH gene.
Conditions associated with SARDH
Gene function
What if the gene works
Inside many cells, the SARDH gene helps manage sarcosine, a natural substance made when your body uses nutrients such as choline. This work takes place in mitochondria, where cells handle many energy and metabolism tasks. Understanding how the SARDH gene helps break down sarcosine makes it easier to see how your body keeps routine cell chemistry in balance.
Inside mitochondria, the SARDH gene helps turn sarcosine into glycine. This is a normal recycling step during everyday nutrient use.
The glycine made in this step can be reused by your cells as a basic building block. It supports routine tasks such as making proteins and other small molecules your body needs.
This reaction also feeds into one-carbon metabolism (a system that moves small carbon units between molecules). That helps cells handle nutrients in a coordinated way during normal metabolism.
What is a variant?
A genetic variant is a minor difference in the DNA sequence of a gene. These differences are common and are part of normal human diversity, including variation in appearance, metabolism, and the way the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. Sometimes, though, a variant changes how a gene works more significantly and can contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the SARDH gene can reduce how well the sarcosine dehydrogenase protein is made, folded, or kept stable inside cells. The way SARDH gene variants affect protein function depends on the change: milder variants may leave some enzyme activity, while more disruptive variants can create a shortened protein or almost no working protein, leading to greater buildup of sarcosine. This larger functional loss is linked to sarcosinemia, which may be more noticeable in some people than in others.
How variants are linked to conditions
Pathogenic variants in the SARDH gene cause sarcosinemia, a very rare inherited condition usually identified when sarcosine levels are high in blood or urine. In studies of how SARDH gene variants are linked to conditions, sarcosinemia is the main well-established diagnosis. Many affected people have few or no symptoms, while some have been reported with developmental or neurologic differences, so day-to-day effects can vary.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are common throughout the general population. Most have no direct impact on health and simply 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 more than one gene and environmental factors are involved. In some situations, however, a single well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence that specific lifestyle or environmental factors increase or reduce risk related to the SARDH gene. For SARDH-related sarcosinemia, risk is mainly linked to inheriting changes in both copies of the gene, one from each parent. Anyone concerned about personal or family risk can speak with a doctor or genetic counselor.
Inheritance of SARDH variants
SARDH-related sarcosinemia is inherited in an autosomal recessive pattern, which means a person usually needs to inherit two changed copies of the SARDH gene, one from each parent. In families asking how SARDH gene variants are inherited, this usually means both parents are healthy carriers. When both parents carry one variant, each pregnancy has a 25% chance of producing a child with the condition, a 50% chance of producing a child who is a carrier, and a 25% chance of producing a child with no familial variant.
What does my SARDH result mean for my family?
For families with a disease-causing SARDH result linked to sarcosinemia, close relatives may also carry the same gene change. Brothers and sisters could be affected or be healthy carriers, and parents are usually carriers when a child has changes in both copies of SARDH. Other relatives may also want to learn whether they carry the family’s SARDH variant, especially when planning a pregnancy.
Genetic information
Genetic testing
How you find out about variants
SARDH genetic testing uses a blood or saliva sample to read the SARDH gene and look for variants. A lab usually uses sequencing, sometimes with extra checks for missing or repeated pieces of the gene, to see whether a change is present. Results may show a benign variant, an uncertain result, or a pathogenic variant linked to sarcosinemia.
When should I consider getting a genetic test?
There is not yet a broadly established reason to get SARDH testing on its own. It may be considered if a child or adult has unexplained high levels of a body chemical called sarcosine on metabolic testing, or if a close family member has a known SARDH change, and the decision is best made with a doctor or genetic counselor.
A genetic result is only one part of your health story
Genetic results can provide useful insight, though their meaning varies with the condition and the kind of variant found. How your body functions over time is also shaped by many factors, including age, lifestyle, environment, and medical history. For some conditions, particularly those affected by many genes, genetic information offers context rather than certainty and makes the most sense when considered with the rest of a person’s care. In other situations, a genetic finding can give a clear answer. In areas like medication response, genetic results may help put personal experiences in context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to medicines. Some people break down a drug more slowly or more quickly than others, so the same dose can lead to different effects. This common part of human biology can influence how well a treatment works or how sensitive someone is to side effects.
What is Pharmacogenetics?
Pharmacogenetics explores how genetic differences can affect a person’s response to medications. It examines 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. You can learn more about this topic in the LearnHub.
Drugs influenced by the SARDH gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting how people respond to medicines, so general questions about side effects, new symptoms, or medication changes are best discussed with your doctor or pharmacist.