The RELN gene gives your body instructions for reelin, a protein that helps guide brain cells into the right place before birth and supports communication between nerve cells later in life. The protein made by this gene helps your cells organize the brain’s layers, so if it does not work properly, brain development can be disrupted. Depending on the variant, this can be linked to developmental delay, low muscle tone, balance problems, seizures, or brain structure differences seen on scans. Some RELN variants are also being studied for their possible role in conditions that affect learning, behavior, and brain development.
What is a gene?
Genes are stretches of DNA that carry information your cells use to make molecules or regulate processes in the body. Some genes provide the instructions for producing proteins, which are the functional parts of cells. Others mainly guide when certain processes happen, where they happen, and how active they are. Taken together, genes influence how the body develops and works, and they can shape how you respond to food, stress, and medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
RELNGene function
What if the gene works
The RELN gene helps guide brain cells into the right place as the brain develops. It also supports communication between nerve cells, which helps with learning, memory, and coordinated movement.
Risk
What if the gene does not work
More severe RELN variants can disrupt brain development, causing lissencephaly with cerebellar underdevelopment and profound developmental delay. Milder variants may be linked to epilepsy or balance and coordination problems.
Treatment
What does that mean for your treatment
No treatment or management approach specific to the RELN gene is currently established for a pathogenic or loss of function variant. The RELN gene is being studied as a marker of brain development and as a possible drug target in some neurologic and psychiatric research.
Conditions associated with RELN
Gene function
What if the gene works
Much of the RELN gene’s work happens as the brain is being built. It helps nerve cells move into the right places, form orderly layers, and make stable connections. This helps explain how the RELN gene supports brain development and later learning.
The RELN gene helps guide young nerve cells to the places where they belong as the brain develops. This careful guidance helps growing brain regions form in an orderly way.
The protein made from the RELN gene helps brain cells settle into organized layers in areas used for thinking, memory, and balance. These layered patterns support smooth communication across brain circuits.
Later in life, the RELN gene supports the strength and flexibility of connections between nerve cells. This helps brain circuits adjust during learning and memory.
What is a variant?
A genetic variant is a minor change in the DNA sequence of a gene. These changes are common and help create normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants have no noticeable effect and are simply part of natural genetic variation. Sometimes, though, a variant changes 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 RELN gene can reduce how much reelin protein a cell makes, disrupt how it folds, or make it harder to release outside the cell, weakening signals that guide brain cell positioning. This helps explain how RELN gene variants affect protein function. Milder variants may leave some activity, while more severe loss-of-function variants can remove most activity; in established RELN-related conditions, that difference can influence which features appear and how early they begin.
How variants are linked to conditions
Disease-causing variants in the RELN gene are best known for causing lissencephaly with cerebellar hypoplasia, a rare inherited brain development condition that can be confirmed by genetic testing. In some families, a single altered copy has also been linked to inherited epilepsy, especially forms with seizures starting in the temporal lobes. The main health conditions linked to RELN gene variants are these rare neurologic conditions, rather than common diseases.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely found in the general population. Most do not directly affect health and simply contribute to natural differences among people. For many genes, having a variant associated with a condition points to a possible link rather than a definite diagnosis, especially when several genes and environmental factors are involved. Still, in some situations, a single well-characterized variant in a specific 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 clearly increase or reduce health risk related to the RELN gene. Risk can vary depending on the exact gene change and family history, and anyone concerned about personal risk may find it helpful to speak with a doctor or genetic counselor.
Inheritance of RELN variants
The inheritance pattern for RELN-related conditions can differ depending on the specific condition and variant type. In families asking how RELN gene variants are inherited, the best-established pattern is autosomal recessive for RELN-related lissencephaly, which means a child usually inherits one changed copy from each parent. RELN has also been linked to some conditions with autosomal dominant inheritance, where one changed copy can be enough and each child of an affected parent has a 50% chance of inheriting it. This means the family pattern can look different from one RELN-related condition to another.
What does my RELN result mean for my family?
For RELN, what this means for relatives depends on the condition linked to the specific result. Some RELN-related conditions run in families in a dominant way, so close relatives may also carry the variant and may want to learn whether testing is relevant for them; some cases can also start new in one person. Other RELN-related conditions happen only when both gene copies are changed, which can mean parents are healthy carriers and brothers or sisters could also be affected or be carriers.
Genetic information
Genetic testing
How you find out about variants
Finding out whether you carry a variant in the RELN gene usually involves RELN gene genetic testing on a blood or saliva sample. A lab reads the DNA sequence to identify variants and may classify them as pathogenic, benign, or of uncertain significance.
When should I consider getting a genetic test?
Genetic testing for the RELN gene may be considered when a child has major brain development differences on MRI, severe developmental delay, low muscle tone, or early seizures, especially if similar problems run in the family. It can also help clarify a diagnosis when doctors suspect a RELN-related condition.
A genetic result is only one part of your health story
A genetic finding can provide useful insight, but how much it reveals depends on the condition and on the type of variant involved. How the body works over time is shaped by many factors, including lifestyle, environment, age, and medical history. In some conditions, especially those influenced 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 like medication response, genetic results can also help put a person’s experiences into perspective.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines, so the same treatment may help one person more than another. Small differences in genes can change how the body breaks down a drug, moves it through the bloodstream, or responds to it at its target. This is common and can influence how well a medication works or how likely someone is to notice side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in a person’s genes can affect the way they respond to medications. It studies gene-drug patterns to help explain why the same treatment may work differently in different people. With many medicines, genes can influence how powerfully a drug works or how the body handles it. This information can support treatment choices that are both more informed and more individualized. More detail on this topic is available in the LearnHub.
Drugs influenced by the RELN gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choice or dose. If you have concerns about side effects, a medicine not working as expected, or changes in your health, talk with your doctor.
History
The history of the RELN gene began with studies of the “reeler” mouse, first described in the 1950s because of its unusual unsteady gait and characteristic brain changes. Initially understood only through visible traits, later recognized as tied to a specific gene, this animal model became central to early research on inherited brain development differences. In the 1990s, scientists identified the RELN gene as the cause of the reeler pattern in mice, which marked a major step in linking a single gene to this well known laboratory finding. Soon after, changes in the RELN gene were also reported in people with a rare condition affecting brain formation. From these first observations, research expanded steadily, and RELN became an important gene in neuroscience and developmental genetics.