The KRT71 gene helps make a strong hair protein inside the hair follicle that supports the shape of each strand as it grows. If this gene does not work properly, hair can grow with an unusual texture or pattern, and some people may have tightly curled, woolly, sparse, or more fragile hair. What this gene does can influence how your hair looks day to day, including curl pattern and overall fullness. Certain variants in the KRT71 gene are linked to inherited hair conditions rather than problems in other parts of the body.
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 code for proteins, the parts of cells that do much of the work. Others mainly control when, where, and how strongly certain activities happen. Taken together, genes influence how the body develops and functions, and they can shape how you respond to food, stress, or medications. To explore this topic more deeply, you can learn more in the LearnHub.
Overview
KRT71Gene function
What if the gene works
The KRT71 gene helps make a structural protein in hair follicles. It supports a layer inside the hair follicle that helps guide how hair grows and contributes to hair texture and shape.
Risk
What if the gene does not work
Variants in the KRT71 gene mainly affect scalp hair, causing tightly curled, coarse, fragile, or sparse hair. Milder and more severe variants can influence how early these changes appear and how noticeable they are.
Treatment
What does that mean for your treatment
No KRT71-specific treatment or drug choice is currently established for people with a pathogenic or loss-of-function variant in the KRT71 gene. Current care is not guided by KRT71 status, and research on the KRT71 gene is focused mainly on hair follicle biology rather than a targeted therapy.
Conditions associated with KRT71
Gene function
What if the gene works
In hair follicles, the KRT71 gene helps make a keratin protein used in the growing hair unit. It is most active in the inner root sheath, a sleeve of cells that surrounds and guides new hair. When this gene works properly, it supports a stable, well-organized setting for normal hair growth.
The KRT71 gene provides instructions for a keratin protein that gives inner root sheath cells strength and shape. This sturdy framework helps these cells hold together around the growing hair.
The protein made from the KRT71 gene is active in the inner root sheath, a layer that closely surrounds a developing hair. In this position, it helps guide the hair as it moves upward through the follicle.
By supporting the structure of the inner root sheath, the KRT71 gene helps the follicle influence the form of the hair shaft. This is a core part of what the KRT71 gene does in hair follicles during normal growth.
What is a variant?
A genetic variant is a minor difference in the DNA sequence of a gene. These differences are common and are part of normal human diversity, including variation in appearance, metabolism, and how the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some cases, 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
Changes in the KRT71 gene can alter how keratin 71 folds and links with other keratin proteins inside hair follicle cells. Some variants in the KRT71 gene affect hair structure by only partly weakening these protein fibers, while more disruptive variants can make the protein unstable or unable to assemble properly. This range in functional impact can influence whether hair changes linked to the KRT71 gene are milder or more noticeable.
How variants are linked to conditions
Variants in the KRT71 gene are linked to inherited hair conditions, especially woolly hair and a form of inherited sparse scalp hair called hypotrichosis simplex. In reports about the KRT71 gene and woolly hair, some pathogenic variants have been shown to cause tightly curled, sparse, or fragile scalp hair from early life. These findings involve rare variants that can help confirm a genetic diagnosis, not common DNA differences.
A variant is not necessarily a diagnosis
Genetic variants are a usual feature of human biology, and they are common across the general population. Most do not directly affect health and instead reflect the natural variation seen among people. For many genes, having a variant associated with a condition points to a possible link rather than a definite diagnosis, particularly when several genes and environmental influences play a role. 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?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the KRT71 gene. Changes in this gene are mainly linked to inherited hair differences, so family history usually matters more than lifestyle or environment.
Inheritance of KRT71 variants
The inheritance pattern for KRT71-related conditions can differ depending on the specific variant and hair condition involved. In families asking how KRT71 gene variants are inherited, the best-established patterns are autosomal dominant for some forms of woolly or sparse scalp hair, and autosomal recessive for certain ectodermal conditions linked to the KRT71 gene. With autosomal dominant inheritance, a parent carrying the variant can pass it to a child of any sex. With autosomal recessive inheritance, a child usually inherits one altered copy from each parent.
What does my KRT71 result mean for my family?
For KRT71, family meaning is usually discussed in an autosomal dominant way for the well-known hair condition linked to this gene. That means close relatives, including a parent, brother, sister, or child, may also carry the same gene change and may have similar hair findings, even if those changes are mild. Each child of someone with a disease-causing KRT71 variant has a 1 in 2, or 50%, chance of inheriting it.
Genetic information
Genetic testing
How you find out about variants
KRT71 genetic testing looks for variants in the KRT71 gene using a blood sample, saliva, or a cheek swab. A laboratory reads the gene’s DNA code and compares it with a usual reference sequence to see whether a variant is present. This test can help explain inherited hair features such as tightly curled, woolly, or sparse scalp hair.
When should I consider getting a genetic test?
Genetic testing may be worth considering if you or your child has unusual scalp hair from early childhood, such as very sparse, fragile, or tightly curled hair, especially when similar hair changes run in the family. Changes in the KRT71 gene are linked to some rare inherited hair conditions and can help clarify the cause.
A genetic result is only one part of your health story
What you can learn from a genetic result varies based on the condition and the specific type of variant involved, even though the result itself can provide valuable insight. How the body functions over time is also shaped by many factors, including lifestyle, environment, age, and medical history. In some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is most useful when viewed alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas like medication response, these results can also help make sense of individual experiences.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body handles certain medicines, which may change how well a treatment works or how likely side effects are. Some people break down a drug more slowly, while others process it faster or respond more strongly at the same dose. This kind of difference is common and is one reason the same medication can feel very effective for one person but less helpful or harder to tolerate for another.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medications. It looks at links between genes and drugs to understand why the same treatment may work differently from one person to another. For many medicines, genes can influence both how strongly a drug works and how the body processes it. This information can support more informed, individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the KRT71 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in how medicines work, so general concerns about your health, treatment, or possible side effects are best discussed with your doctor.