The TMEM216 gene helps cells build and use tiny hair-like structures called cilia, which act like sensors and help guide early body development. This gene plays an important role in how the brain, kidneys, liver, and other organs form and work. If you inherit a harmful variant in both copies of the TMEM216 gene, it can cause a ciliopathy such as Joubert syndrome or Meckel syndrome, with features that may include low muscle tone, breathing changes, developmental differences, and kidney or liver problems.
What is a gene?
A gene is a piece of DNA that carries instructions your cells use to make molecules or regulate activities in the body. Some genes provide the directions for producing proteins, which are the working parts of cells. Others mainly help determine when certain activities take place, where they take place, and how active they are. Together, genes affect how the body develops and functions, and they can influence how you respond to food, stress, or medications. For a deeper look at this topic, you can learn more in the LearnHub.
Overview
TMEM216Gene function
What if the gene works
The TMEM216 gene helps cells build and organize cilia, tiny structures that sense signals. This supports early development and the normal function of organs such as the brain, kidneys, and eyes.
Risk
What if the gene does not work
Variants in the TMEM216 gene can cause conditions linked to faulty cilia, most often Joubert syndrome and, in more severe cases, Meckel syndrome. Effects may range from low muscle tone and developmental delay to major brain, kidney, liver, and limb changes.
Treatment
What does that mean for your treatment
For people with a pathogenic or loss-of-function variant in the TMEM216 gene, no TMEM216-specific treatment or drug-selection approach is currently established. Management is based on the person’s symptoms and affected organs rather than on a TMEM216-targeted medicine.
Conditions associated with TMEM216
Gene function
What if the gene works
Many cells in your body use the TMEM216 gene to build and run tiny surface antennas called cilia. These structures help cells sense their surroundings and pass along signals, so understanding how the TMEM216 gene supports cilia helps explain its role in everyday growth and cell organization.
The TMEM216 gene helps position the base of a cilium at the cell surface so the structure can form correctly. This gives the cell a stable starting point for building its tiny signaling antenna.
Its protein sits near the base of the cilium and helps create a controlled entry point. This helps the cell move the right proteins into and out of the cilium at the right time.
By keeping cilia properly assembled, the TMEM216 gene supports how cells detect outside cues and pass messages inward. This is part of normal growth and the way cells coordinate with nearby cells.
What is a variant?
A genetic variant is a small difference in the DNA sequence within a gene. These differences are common and help shape normal human diversity, such as variation in appearance, metabolism, or how 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 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
Research on how TMEM216 gene variants affect cilia function shows that some changes reduce protein stability or its placement at the base of cilia, the tiny hairlike structures used for signaling. More severe variants can leave little or no working protein, while milder variants may preserve partial function. This range can change how cell signaling is disturbed and may help explain why TMEM216-related Joubert syndrome or Meckel syndrome can vary in how early features appear and how broad they are.
How variants are linked to conditions
Pathogenic variants in the TMEM216 gene can cause Joubert syndrome and have also been found in some people with Meckel syndrome. These are inherited conditions that can affect early development and may involve the brain, eyes, kidneys, liver, or extra fingers or toes. In this setting, TMEM216 gene variants are used to help confirm the diagnosis rather than to estimate a small change in risk.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are common throughout the general population. Most do not directly affect health and simply reflect natural human diversity. For many genes, carrying a variant associated with a condition suggests a possible link rather than a certain diagnosis, especially when more than one gene and environmental factors play a role. In some situations, though, a single well understood variant in a specific gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For conditions linked to the TMEM216 gene, risk is mainly shaped by the variants inherited at birth. Family history and whether both biological parents carry a TMEM216 change matter most, and there is not broadly confirmed evidence that lifestyle factors change this genetic risk.
Inheritance of TMEM216 variants
Variants in the TMEM216 gene are inherited in an autosomal recessive pattern for the well-established TMEM216-related conditions. This means a child usually inherits one altered copy from each parent, and the parents are often healthy carriers. When both parents carry a TMEM216 gene variant, each pregnancy has a 25% chance of the child inheriting both altered copies, a 50% chance of being a carrier, and a 25% chance of inheriting neither altered copy. Because the TMEM216 gene is on an autosome rather than a sex chromosome, this inheritance pattern is the same for boys and girls.
What does my TMEM216 result mean for my family?
Changes in the TMEM216 gene are linked to inherited conditions that usually run in families in a recessive pattern. For family members, this often means parents can be healthy carriers, and brothers, sisters, or future children may also be affected or be carriers. Close relatives may want to learn whether the same gene change is present in their family.
Genetic information
Genetic testing
How you find out about variants
To find TMEM216 variants, labs use genetic testing on a blood sample, saliva, or cheek swab. TMEM216 genetic testing reads the DNA code of the TMEM216 gene and compares it with the usual sequence to look for changes linked to inherited conditions. Results may show a pathogenic variant, a benign variant, or an uncertain finding.
When should I consider getting a genetic test?
Consider TMEM216 testing if a baby or child has signs of Joubert or a related condition, such as low muscle tone, delayed development, unusual breathing or eye movements, or certain brain, kidney, or liver findings. It can also help when there is a family history of these conditions or for carrier screening before pregnancy in at-risk families.
A genetic result is only one part of your health story
Genetic findings can provide meaningful insight, but how much they reveal varies by the condition and by the type of variant involved. Many other factors, including age, medical history, environment, and lifestyle, also shape how the body works over time. 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 may give a clear answer. In areas such as medication response, genetic results can also help place individual experiences in 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 reacts to it at the target tissue. This helps explain why the same treatment may work well for one person, have less effect in another, or cause more side effects in someone who is more sensitive to it.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medications. It focuses on relationships between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medicines, genes influence both how strongly a drug works and how the body processes it. This information can support more informed, individualized treatment decisions. More details on this topic are available in the LearnHub.
Drugs influenced by the TMEM216 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in how medicines work, so questions about symptoms, side effects, or treatment choices are best discussed with your doctor.
History
In 2010, researchers identified the TMEM216 gene as a cause of some cases of Joubert syndrome and Meckel syndrome, helping connect two rare inherited conditions that had long been described by their features. In recent decades, awareness of this gene’s role has grown as studies of these conditions became more precise. Early reports showed that TMEM216 variants could appear in families from different backgrounds, including a founder variant seen in some Hutterite families. Building on this early work, scientists linked TMEM216 to a group of conditions now recognized as ciliopathies, which brought clearer genetic classification. Over time, descriptions became more precise as newer sequencing methods made it easier to identify TMEM216 variants in affected families.