The LZTFL1 gene helps cells manage cilia, tiny structures on the cell surface that send and receive signals. This gene plays an important role in normal cell signaling, so if it does not work properly, it can contribute to Bardet-Biedl syndrome, which may affect vision, weight, kidney function, and learning. Public awareness of the LZTFL1 gene grew during the COVID-19 pandemic when studies linked DNA changes near this gene to a higher chance of severe COVID-19.
What is a gene?
Genes are stretches of DNA that give your cells the instructions to make molecules or manage processes in the body. Some genes carry the information needed to produce proteins, the parts of cells that do much of the work. Others mainly guide when certain processes happen, where they take place, and how strongly they run. Together, genes affect how the body develops and functions, and they can influence how you respond to food, stress, or medications. To explore this subject further, you can learn more in the LearnHub.
Overview
LZTFL1Gene function
What if the gene works
The LZTFL1 gene helps move certain proteins to the primary cilium, a tiny antenna on many cells. This supports cell signaling and helps cells lining organs such as the lungs keep their normal structure.
Risk
What if the gene does not work
More severe variants in the LZTFL1 gene can cause Bardet-Biedl syndrome, linked to vision loss, extra fingers or toes, weight gain, kidney problems, and delayed development. Milder variants may change which features appear and when they start.
Treatment
What does that mean for your treatment
No treatment or management approach is currently established specifically for pathogenic variants in the LZTFL1 gene. The LZTFL1 gene is being studied as a biomarker and possible drug target in some cancers, but this has not changed routine treatment choices.
Conditions associated with LZTFL1
Gene function
What if the gene works
In many cells, the LZTFL1 gene helps manage activity around primary cilia, which are tiny antenna structures on the cell surface. These structures help cells sense and respond to signals from nearby tissues. This helps explain what the LZTFL1 gene does in the body during everyday cell communication.
The LZTFL1 gene helps control how certain proteins move into and out of primary cilia. This keeps the cilium organized so it can handle routine cell signaling in a steady way.
By organizing proteins at the cilium, the LZTFL1 gene supports how cells receive and pass along outside signals. This is part of how cells respond to nearby cues during normal tissue activity.
Inside cells, the LZTFL1 gene helps guide the BBSome (a group of proteins that carries cargo) near the cilium. This supports the controlled delivery and return of selected proteins at the cell surface.
What is a variant?
A genetic variant is a slight difference in the DNA sequence of a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants do not cause any noticeable effects and simply represent natural genetic variation. In some situations, though, a variant can change how a gene functions more significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the LZTFL1 gene can lower the amount of working protein or change its shape, which may weaken how it helps move key proteins within the cilium, a small cell structure that senses signals. Milder variants may leave some activity, while more severe variants can reduce protein stability or stop production altogether. When both copies are strongly affected, this deeper disruption can contribute to earlier or broader features of Bardet-Biedl syndrome.
How variants are linked to conditions
Pathogenic variants in the LZTFL1 gene can cause Bardet-Biedl syndrome, a genetic condition that can affect vision, weight, kidney health, learning, and sexual development. In this setting, LZTFL1 gene variants are linked to Bardet-Biedl syndrome when a person inherits disease-causing variants in both copies of the gene. Some features vary from person to person, even within the same family.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely found across the general population. Most do not have a direct impact on health and simply reflect natural human diversity. For many genes, carrying a variant associated with a condition points to a possible link rather than a confirmed diagnosis, especially when several genes and environmental factors contribute. In some situations, though, a single 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 risk directly related to the LZTFL1 gene. For many living with a LZTFL1 change, overall health factors and the condition involved still matter, so personal risk is best discussed with a doctor or genetic counselor.
Inheritance of LZTFL1 variants
For families wanting to understand how LZTFL1 gene variants are inherited, the well-established disease pattern is autosomal recessive. This means a person usually develops an LZTFL1-related condition only when they inherit one changed copy of the LZTFL1 gene from each parent. Parents who each carry one variant are often unaffected, and with each pregnancy they have a 25% chance of having an affected child, a 50% chance of having a child who is a carrier, and a 25% chance of having a child without the familial variants. Sons and daughters are affected at similar rates.
What does my LZTFL1 result mean for my family?
Changes in the LZTFL1 gene have been linked to a rare inherited condition called Bardet-Biedl syndrome, which usually runs in families in a recessive pattern. For family members, this often means parents can carry the gene change without having symptoms, and brothers or sisters may also be affected or be carriers. Other close relatives may also carry the same change.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for variants in the LZTFL1 gene uses DNA from a saliva or blood sample to look for changes in that gene. This LZTFL1 genetic test can show whether a specific variant is present, and the result is then interpreted to see if the change is likely benign or linked to health.
When should I consider getting a genetic test?
Genetic testing for the LZTFL1 gene may be worth considering when someone has signs of Bardet-Biedl syndrome, such as extra fingers or toes, early vision problems, kidney issues, or delayed development. It can also help when this condition runs in the family.
A genetic result is only one part of your health story
Genetic results can provide valuable insight, although what they reveal varies depending on the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, influence how the body functions over time. In some conditions, especially those shaped by many genes, genetic information offers context rather than certainty and is most useful when viewed together with other parts of care. In other situations, a genetic result can give a clear answer. In areas like medication response, genetic results can also help put personal experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. This helps explain why the same treatment works well for one person, seems weaker for another, or causes more side effects in someone else. Small inherited differences can change how the body breaks down a medicine, moves it through the body, or responds to it at its target, and these differences are common.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences shape the way a person responds to medicines. It studies connections between genes and drugs to better explain why the same treatment can work differently from one person to another. For many medications, genes influence either how strongly a drug works or how the body processes it. This information can support treatment decisions that are more informed and more individualized. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the LZTFL1 gene
When should I seek medical advice?
There isn't yet a broadly confirmed role for this gene in predicting how medicines will work. If you have questions about side effects, a new prescription, or changes in your health, talk with your doctor or pharmacist.
History
The LZTFL1 gene was little known outside research settings for many years. Public conversations shifted after a major news story focused on this gene during the COVID-19 pandemic. In 2020, large genetic studies linked a region on chromosome 3 that includes the LZTFL1 gene with a higher chance of severe illness from COVID-19. Soon after, researchers reported that this risk-linked stretch of DNA was inherited from Neanderthals, which brought the gene even more attention. From these first observations, research expanded steadily as scientists worked to separate the effect of the LZTFL1 gene from nearby genes in the same region. That period made the LZTFL1 gene part of a broader public discussion about inherited differences in infection risk.