The MYD88 gene helps immune cells pass along danger signals, so your body can respond to germs and inflammation in a timely way. This gene helps your body turn on early defense signals after certain immune sensors detect bacteria or viruses. If the MYD88 gene does not work properly from birth, people may have an inherited immune condition with repeated bacterial infections, especially in childhood. Some acquired MYD88 variants can also help drive certain blood cancers, including Waldenström macroglobulinemia.
What is a gene?
Genes are pieces of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes provide the directions for producing proteins, the parts of cells that do the work. Other genes mainly control when, where, and how strongly certain processes take place. Together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
MYD88Gene function
What if the gene works
The MYD88 gene helps immune cells pass along early danger signals. This supports inflammation and helps your body fight infections.
Risk
What if the gene does not work
Inherited variants in the MYD88 gene can weaken early immune signaling, often leading to repeated bacterial infections in childhood, with effects ranging from milder to more severe. Certain acquired variants in the MYD88 gene can also help drive some B cell blood cancers.
Treatment
What does that mean for your treatment
In Waldenström macroglobulinemia, the MYD88 L265P variant can help guide use of BTK inhibitors such as ibrutinib or zanubrutinib. People whose cancer lacks MYD88 L265P often have lower response rates to these drugs, so treatment choices may differ.
Conditions associated with MYD88
Gene function
What if the gene works
Inside immune cells, the MYD88 gene helps pass along early warning signals. When it is working as expected, cells can turn outside alerts into clear instructions inside the cell. This supports a prompt, organized response to germs and other signs that the body needs immune attention.
The protein made from the MYD88 gene acts like a messenger link between immune sensors and the cell’s inner signaling system. This lets cells pass along warning signals after they detect germs or signs of tissue stress.
Once that message is passed on, the MYD88 gene helps switch on genes that make cytokines (immune messenger proteins). These messages help call in immune cells and organize a controlled early inflammatory response.
By helping cells respond within minutes to hours, the MYD88 gene supports the body’s first line of defense. This is central to the MYD88 gene’s role in the immune system during everyday exposure to microbes.
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 responds to environmental influences. Many variants do not have any noticeable effect and are simply part of natural genetic variation. At times, though, a variant changes how a gene works more significantly and may contribute to, or cause, a genetic condition.
Genetic variants
What if the gene does not work
Variants in the MYD88 gene can either weaken the MYD88 protein or make it signal too strongly. How MYD88 gene variants affect protein signaling depends on the change: milder variants may partly reduce signaling, while more disruptive variants can shut it down, and some changes such as MYD88 p.Leu265Pro can leave signaling stuck in the on position. These differences can influence whether immune problems linked to MYD88 or certain blood cancers appear earlier or in a more pronounced way.
How variants are linked to conditions
Pathogenic variants in the MYD88 gene can cause a rare inherited immune condition called MYD88 deficiency, which is linked to repeated bacterial infections that often begin in childhood. Separate acquired changes, especially MYD88 L265P found in blood or bone marrow cells, are strongly linked to Waldenström macroglobulinemia and are also seen in some diffuse large B cell lymphomas. Inherited and acquired MYD88 gene variants are linked to very different health conditions.
A variant is not necessarily a diagnosis
Variants in genes are a routine part of human biology and occur widely across the general population. Most do not directly affect health and instead reflect natural variation among people. For many genes, having a variant associated with a condition points to a possible link rather than a confirmed diagnosis, particularly when more than one gene and environmental influences contribute. In other situations, 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?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risks related to the MYD88 gene. In families with a disease-causing MYD88 change, risk is mainly linked to the variant itself, and personal guidance from a doctor or genetic counselor can help clarify what it means for you.
Inheritance of MYD88 variants
For inherited MYD88-related disease, the MYD88 inheritance pattern is autosomal recessive. This means a child must inherit two changed copies of the MYD88 gene, one from each parent, to have the condition. Parents who carry one changed copy are usually healthy carriers. When both parents are carriers, each pregnancy has a 25% chance of an affected child, a 50% chance of a carrier child, and a 25% chance of a child who did not inherit either changed copy.
What does my MYD88 result mean for my family?
If your MYD88 result is linked to the rare inherited immune condition caused by this gene, family members can sometimes carry the same change. Parents are often healthy carriers, and brothers or sisters may also be affected or be carriers, so relatives may want to discuss family testing. The meaning for family members is different from MYD88 changes found only in cancer cells, which are not usually passed down.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a change in the MYD88 gene, doctors use MYD88 genetic testing on blood, saliva, or a tissue sample. A lab reads the gene's DNA code and checks for specific variants or larger changes. Results may show a pathogenic variant, a benign variant, or no relevant change.
When should I consider getting a genetic test?
Genetic testing for the MYD88 gene may be considered if someone has had repeated, severe bacterial infections starting in childhood, especially with a family history of similar infections. Doctors may also test MYD88 in blood or bone marrow samples when certain blood cancers are being investigated.
A genetic result is only one part of your health story
Genetic findings can be informative, but what they tell you varies based on the condition and the kind of variant involved. Over time, how the body works is also shaped by many factors, including lifestyle, environment, age, and medical history. In some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best viewed alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas like medication response, genetic results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to medicines. Small differences in genes can change how a drug is absorbed, broken down, moved through the body, or how strongly it acts on its target. This helps explain why the same medication may work well for one person, seem less effective for another, or cause more side effects in someone else.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in a person’s genes affect the way medications work. It studies gene-drug patterns to help explain why the same treatment can have different effects in different people. With many medicines, genes influence either how the body handles a drug or how much effect the drug has. This information can support treatment choices that are better informed and more individualized. More detail on this topic is available in the LearnHub.
Drugs influenced by the MYD88 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, treatment changes, or how well a medicine is working are best discussed with your doctor. MYD88 is being studied in some blood cancers to see whether certain gene changes relate to response to targeted treatments, but this is not a routine guide for everyday prescribing.
History
The MYD88 gene entered medical research in the 1990s, when scientists studying early immune cell responses identified a gene that switched on quickly during myeloid cell development. It was first described as part of this early response, which is why it was given the name MYD88. Building on this early work, scientists uncovered more about the gene as research on inflammation and infection expanded, linking it to major immune signaling pathways. In the 2000s, MYD88 became an important part of basic immunology research because it helped connect findings from infection studies to inherited immune conditions. A major later milestone came in 2012, when a recurrent MYD88 variant, L265P, was reported in many people with Waldenström macroglobulinemia, bringing the gene into cancer genetics as well.