The MEI1 gene helps the body make healthy sperm and eggs by supporting meiosis, the special cell division that gives each egg or sperm the right amount of DNA. If this gene does not work properly, those cells may not develop normally. People with harmful variants in the MEI1 gene may have infertility, including little or no sperm production in men or problems with egg development in women. This gene is mainly discussed in fertility medicine rather than in everyday public culture.
What is a gene?
A gene is a stretch of DNA that carries instructions your cells use to make molecules or regulate activities in the body. Some genes contain the directions for producing proteins, the parts of cells that do the work. Others mainly control when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body develops and works, and they can also shape how you respond to food, stress, or medications. To explore this topic in more detail, you can learn more in the LearnHub.
Overview
MEI1Gene function
What if the gene works
The MEI1 gene helps the body make sperm and egg cells through meiosis, the special cell division used for reproduction. It supports chromosome pairing and the safe exchange of genetic material.
Risk
What if the gene does not work
Pathogenic variants in the MEI1 gene can disrupt meiosis, often causing infertility from absent sperm production and, in some women, primary ovarian insufficiency. Effects can range from isolated infertility to earlier ovarian failure, depending on the variant.
Treatment
What does that mean for your treatment
No MEI1-specific treatment or drug selection approach is currently established; care is guided by the person’s fertility findings rather than a targeted therapy for the MEI1 gene.
Conditions associated with MEI1
Gene function
What if the gene works
During egg and sperm formation, the MEI1 gene helps reproductive cells move through meiosis, the special cell division that halves the chromosome number. It supports early steps that let matching chromosomes meet and exchange small pieces of DNA. This keeps the process orderly as cells prepare genetic material for the next generation.
The MEI1 gene helps start meiosis, the special cell division used to make eggs and sperm. This early step is a core part of MEI1 gene function in human reproduction.
Inside reproductive cells, the MEI1 gene helps create tiny planned cuts in DNA. These cuts allow matching chromosome pairs to exchange small DNA segments as eggs and sperm form.
By helping DNA exchange begin, the MEI1 gene supports the close pairing of matching chromosomes during meiosis. This pairing helps cells separate chromosomes in an organized way so each egg or sperm carries one set.
What is a variant?
A genetic variant is a minor change in the DNA sequence of a gene. These changes are common and help shape normal human diversity, such as differences in appearance, metabolism, or how the body responds to environmental influences. Many variants have no noticeable effect and are simply part of natural genetic variation. Sometimes, however, a variant can change how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the MEI1 gene can weaken or stop a protein needed for meiosis, the special cell division that makes eggs and sperm. Many MEI1 gene variants appear to disrupt the controlled DNA cuts that let matching chromosomes pair correctly, which can lead to meiotic arrest, meaning the cells stop developing. Milder variants may leave some activity, while more severe variants can shut this process down more fully and are often linked to earlier or more complete infertility.
How variants are linked to conditions
Pathogenic variants in the MEI1 gene are most clearly tied to inherited infertility. In people assigned male at birth, having disease-causing variants in both copies of the MEI1 gene can cause spermatogenic failure with nonobstructive azoospermia, meaning semen contains no sperm because sperm production is disrupted. This is the main MEI1 gene condition association reported consistently in human genetics studies.
A variant is not necessarily a diagnosis
DNA variants are a routine part of human biology and are widely found in the general population. Most do not directly affect health and instead reflect natural human variation. For many genes, having a variant associated with a condition points to a possible link rather than a certain diagnosis, especially when several genes and environmental factors are involved. In some 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?
For MEI1, risk is mainly linked to whether someone has inherited harmful changes in both copies of the gene, which can lead to some forms of infertility. There is not yet broadly confirmed evidence that lifestyle or environmental factors clearly increase or reduce MEI1-related risk, so people with concerns about family history or fertility may benefit from speaking with a doctor or genetic counselor.
Inheritance of MEI1 variants
MEI1 gene inheritance usually follows an autosomal recessive pattern for the conditions currently linked to this gene. This means a person inherits one MEI1 gene variant from each parent, while parents who carry just one variant are usually unaffected carriers. When both parents are carriers, each pregnancy has a 25% chance of a child inheriting both variants, a 50% chance of being a carrier, and a 25% chance of inheriting neither variant. Because the MEI1 gene is on an autosome, this can affect sons and daughters alike.
What does my MEI1 result mean for my family?
For MEI1, family implications are usually linked to a recessive pattern. This often means parents are healthy carriers, and brothers or sisters may also be carriers or, less often, have the same fertility-related condition if they inherited two changed copies. For many living with a MEI1 result, children are unlikely to be affected unless the other biological parent also carries a MEI1 change.
Genetic information
Genetic testing
How you find out about variants
Variants in the MEI1 gene are usually found through MEI1 genetic testing for infertility, often using a blood or saliva sample. A lab reads the DNA code in the MEI1 gene and compares it with the usual sequence to look for variants. Results may show a pathogenic variant, a benign change, or a variant of uncertain significance.
When should I consider getting a genetic test?
Testing may be worth discussing if there is severe infertility, especially in a man with no sperm in the semen because sperm production seems to stop early, or if this pattern runs in the family. A MEI1 result can sometimes help explain the cause and is usually checked as part of a broader infertility genetics evaluation.
A genetic result is only one part of your health story
A genetic result can provide useful insight, but what it shows depends on the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, influence how the body works over time. For some conditions, especially those shaped by many genes, genetic information offers context rather than certainty and is best understood together with other parts of care. In other situations, a genetic result may give a clear answer. In areas such as medication response, genetic results can 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 DNA can change how the body breaks down a drug, moves it through the bloodstream, or responds at the drug’s target. This helps explain why the same medication may work well for one person, work less well for another, or cause more side effects in someone else.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medications. It studies relationships between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medicines, genes influence both how strongly a drug works and how the body handles it. This information can support more informed and more individualized treatment decisions. More detail on this topic is available in the LearnHub.
Drugs influenced by the MEI1 gene
When should I seek medical advice?
There is no broadly confirmed role for this gene in predicting how medicines will work, so questions about treatments, side effects, or medication changes are best discussed with your doctor or pharmacist.