The ADAMTS13 gene helps keep blood clotting under control by making a protein that cuts very large von Willebrand factor strands into smaller pieces. When the gene does not work well, these strands can stay too sticky, and tiny clots may form in small blood vessels. This gene plays an important role in protecting the brain, kidneys, and other organs from this problem. Rare severe variants in the ADAMTS13 gene can cause inherited thrombotic thrombocytopenic purpura, a condition that can lead to low platelets, anemia, and episodes of organ injury.
What is a gene?
A gene is a section of DNA that gives your cells instructions for making molecules or guiding processes throughout the body. Some genes provide the directions for producing proteins, which are the parts of cells that do much of the work. Others mainly regulate when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body grows and works, and they can influence how you respond to food, stress, and medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
ADAMTS13Gene function
What if the gene works
The ADAMTS13 gene helps make a blood protein that trims von Willebrand factor, a clotting helper. This helps keep clotting balanced and supports smooth blood flow in small vessels.
Risk
What if the gene does not work
More disruptive variants in the ADAMTS13 gene can cause inherited thrombotic thrombocytopenic purpura, where tiny blood clots form throughout the body. Symptoms may range from mild episodes to earlier, more frequent anemia, bruising, low platelets, kidney problems, or neurologic symptoms.
Treatment
What does that mean for your treatment
Pathogenic variants in the ADAMTS13 gene can make ADAMTS13 replacement central to care, using plasma infusions or recombinant ADAMTS13. Ongoing preventive treatment may be used, especially around pregnancy, surgery, or past episodes, and immune targeting drugs used for acquired TTP are not the main treatment here.
Conditions associated with ADAMTS13
Gene function
What if the gene works
In everyday life, the ADAMTS13 gene helps keep blood clotting balanced. It gives your body instructions for a protein that fine tunes how platelets interact with von Willebrand factor, a blood protein involved in clotting. This is part of how the ADAMTS13 gene helps control blood clotting and blood flow in tiny vessels.
Its protein cuts von Willebrand factor, a blood protein that helps platelets stick at an injury site. This trims large strands down to a workable size and keeps clotting signals more controlled.
By adjusting von Willebrand factor in the bloodstream, ADAMTS13 helps limit how many platelets gather in one spot at one time. This supports normal blood clotting when needed while keeping platelet sticking in balance.
ADAMTS13 works especially in small blood vessels, where blood flow stretches von Willebrand factor into long strands. Cutting those strands helps blood move more smoothly through the smallest parts of the circulation.
What is a variant?
A genetic variant is a minor difference in the DNA sequence of a gene. These changes are common and help explain normal differences among people, such as appearance, metabolism, or how the body responds to environmental factors. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some situations, though, a variant can affect how a gene works more substantially and may contribute to, or cause, a genetic condition.
Genetic variants
What if the gene does not work
How ADAMTS13 gene variants affect enzyme activity depends on the specific DNA change. Some make the protein fold poorly, break down early, or fail to leave the cell, while others weaken how well it cuts von Willebrand factor, a blood clotting protein. Milder variants may leave some activity, but more severe variants can nearly abolish it. This often influences whether congenital thrombotic thrombocytopenic purpura appears earlier and with more pronounced episodes.
How variants are linked to conditions
Pathogenic variants in the ADAMTS13 gene cause congenital thrombotic thrombocytopenic purpura, also called inherited TTP or Upshaw-Schulman syndrome. This ADAMTS13 gene condition can lead to episodes of very low platelets, red blood cell breakdown, bruising, fatigue, confusion, stroke-like symptoms, or kidney problems. Symptoms may begin in infancy or childhood, though some people are first diagnosed in adulthood, often during triggers such as infection or pregnancy.
A variant is not necessarily a diagnosis
Genetic variants are common across the general population and are a normal feature of human biology. Most do not directly affect health and simply contribute to natural differences among people. For many genes, a variant associated with a condition points to a possible link rather than a certain diagnosis, particularly when several genes and environmental influences also play a role. In some situations, though, one well-characterized variant in a particular gene is enough to confirm the diagnosis.
Are there things that can increase or change my risk?
For people with harmful changes in both copies of the ADAMTS13 gene, the chance of developing this clotting condition is mainly set by the gene change itself. Episodes can still be brought on or worsened by triggers such as infection, pregnancy, surgery, or some medicines. There is not enough evidence to say lifestyle changes lower the inherited risk.
Inheritance of ADAMTS13 variants
ADAMTS13-related inherited thrombotic thrombocytopenic purpura is passed down in an autosomal recessive pattern. This means a child usually inherits one ADAMTS13 gene variant from each parent, and parents who carry one variant typically do not have the condition themselves. When both parents are carriers, each pregnancy has a 25% chance of the child inheriting both variants and having the condition, a 50% chance of being a carrier, and a 25% chance of inheriting neither variant. This is the main answer to how ADAMTS13 variants are inherited in families.
What does my ADAMTS13 result mean for my family?
For families with an ADAMTS13-related condition, close relatives may also carry the changed gene, even if they have never had symptoms. Brothers and sisters may be affected or may be carriers, and parents are usually carriers. Family members may want to learn whether the same ADAMTS13 change is present, especially if there is a history of unexplained low platelets, anemia, or clotting problems.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a variant in the ADAMTS13 gene, a lab can analyze DNA from a blood sample, saliva sample, or cheek swab. ADAMTS13 genetic testing reads the gene's code and compares it with the usual sequence to identify variants that may help explain test results or support a diagnosis.
When should I consider getting a genetic test?
Genetic testing for the ADAMTS13 gene may be worth considering if someone has repeated episodes of a rare clotting condition called thrombotic thrombocytopenic purpura, especially if it started in childhood, happened during pregnancy, or runs in the family. It can help confirm an inherited form and clarify whether relatives may also carry it.
A genetic result is only one part of your health story
A genetic finding can provide useful information, but how much it explains depends on the condition and the kind of variant involved. Age, environment, lifestyle, and medical history also affect 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 considered alongside other parts of care. In other situations, a genetic result may give a clear answer. In areas like medication response, it can also help put personal experiences into perspective.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Some people break down a drug more slowly or more quickly, while others may be more or less sensitive to its effects. This helps explain why the same treatment works well for one person but not as well for another, or why side effects can differ. These differences are common and are one part of how the body handles medication.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can affect the way a person responds to medications. It studies connections between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medicines, genes can influence how strongly a drug works or how the body handles it. This information can support treatment decisions that are more informed and more individualized. More on this topic is available in the LearnHub.
Drugs influenced by the ADAMTS13 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medicine choice or predicting medication response. If you have concerns about your health, side effects, or how a treatment may affect you, it is best to discuss them with your doctor.
History
For many years, doctors described a rare clotting illness now called thrombotic thrombocytopenic purpura, or TTP, before its inherited cause was clear. Initially understood only through visible traits, later recognized as tied to a specific gene, this condition became much easier to study in the late 20th century. Researchers then identified the missing blood protein activity and linked it to the ADAMTS13 gene in the early 2000s. That discovery helped explain why some people had inherited TTP, while others developed a similar illness later in life for different reasons. From these first observations, research expanded steadily, and ADAMTS13 testing became part of confirming inherited cases. This work marked an important step in connecting unusual clotting patterns with a specific genetic cause.