The PADI3 gene helps hair follicles shape and strengthen the hair shaft. This gene plays an important role in slightly changing certain hair proteins as hair forms. If it does not work properly, hair may grow in a dry, frizzy way that stands away from the scalp and is hard to comb flat. Some people who inherit nonworking copies of the PADI3 gene from both parents have uncombable hair syndrome, a rare condition that often starts in childhood.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes hold the instructions for producing proteins, the parts of cells that do much of the work. Others mainly help determine when certain processes happen, where they take place, and how strongly they occur. Taken together, genes affect how the body develops and works, and they can shape how you respond to food, stress, or medications. To explore this subject in more detail, you can find more in the LearnHub.
Overview
PADI3Gene function
What if the gene works
The PADI3 gene helps make and shape the hair shaft. Its protein changes certain hair proteins in hair follicles, which supports normal hair texture and strength.
Risk
What if the gene does not work
When the PADI3 gene does not work properly, hair shaft formation is disrupted. Milder and more severe variants can affect hair differently, from uncombable hair syndrome with dry, frizzy hair in childhood to some forms of scarring hair loss.
Treatment
What does that mean for your treatment
For people with a pathogenic variant in the PADI3 gene, no PADI3-specific treatment or drug choice is currently established in clinical guidelines. Research is mainly focused on how the PADI3 gene shapes hair shaft formation, rather than on targeted medicines used in routine care.
Conditions associated with PADI3
Gene function
What if the gene works
In hair follicles and the outer layer of skin, the PADI3 gene helps certain proteins go through a final shaping step. It changes one protein building block, which can alter how tightly that protein folds or packs. This helps explain the PADI3 gene's role in normal hair shaft formation and skin maturation.
The PADI3 gene changes selected protein building blocks from arginine to citrulline. This small edit can reshape proteins so they suit maturing hair and skin cells.
In developing hair follicles, PADI3 works on trichohyalin (a structural hair protein). This helps support the shaping of cells that guide the hair shaft as it forms.
In the outer skin, PADI3 helps proteins adjust during the last stages of skin cell development. This supports the normal makeup of the skin surface and its protective outer layer.
What is a variant?
Genetic variants are small changes in a gene’s DNA sequence. They are common and help shape normal differences among people, including variation in appearance, metabolism, and how the body responds to environmental influences. Many have no noticeable effect and are simply part of natural genetic variation. In some cases, though, a variant changes how a gene works more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
PADI3 gene variants can change the protein’s shape or make cells produce less of it, which may weaken its enzyme activity in the hair follicle. Some changes also disrupt calcium driven activation or reduce binding to key hair shaft proteins. Milder variants may leave partial activity, while more disruptive variants can greatly reduce function and are more often linked to clearer or earlier hair shaft changes, including in some people with uncombable hair syndrome.
How variants are linked to conditions
Pathogenic variants in the PADI3 gene cause uncombable hair syndrome, a rare hair condition that usually starts in childhood. This condition linked to the PADI3 gene mainly affects hair texture and appearance, with hair that is dry, frizzy, stands away from the scalp, and is hard to smooth or comb flat. Finding a disease-causing PADI3 variant in the right clinical setting can help confirm the diagnosis.
A variant is not necessarily a diagnosis
Variants in genes are a usual part of human biology and are widely found in the general population. Most do not directly affect health and simply reflect natural human diversity. 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 play a role. In some situations, though, one well understood variant in a particular gene can be 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 PADI3 gene. Changes in this gene have been linked to certain hair conditions, but how much risk they cause and what might modify that risk can vary.
Inheritance of PADI3 variants
PADI3-related hair conditions, including some cases of uncombable hair syndrome, are usually inherited in an autosomal recessive pattern. In practical terms, how PADI3 gene variants are inherited means a child usually receives one altered copy from each parent, and the parents are often healthy carriers. When both parents carry a PADI3 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. Sons and daughters are affected at the same rate.
What does my PADI3 result mean for my family?
For PADI3, the best-established family pattern is linked to a rare hair condition called uncombable hair syndrome, which usually runs in families in a recessive way. This often means parents do not have the condition themselves but can each carry one changed copy of the gene. Brothers and sisters may also have the condition or be carriers, and other relatives may be carriers too.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for PADI3 variants usually uses a blood sample or cheek swab to examine the PADI3 gene for changes in its DNA code. A lab may test only this gene or include it in a larger gene panel. Results can show a benign variant, a health related variant, or an unclear finding that needs more study.
When should I consider getting a genetic test?
Genetic testing for the PADI3 gene may be worth considering when a child has hair from early childhood that is very dry, frizzy, stands away from the scalp, and cannot be combed flat, especially if this runs in the family. It can help confirm a cause of uncombable hair syndrome when the reason for the hair changes is unclear.
A genetic result is only one part of your health story
Genetic results can provide useful insight, but what they tell you depends on the condition and the kind of variant involved. Over time, how the body works is shaped by many factors, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is best considered along with other parts of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, genetic results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Some people break down a drug faster or slower than others, which can change how much of the medicine reaches the body and how long it stays active. This is a common reason the same treatment may work well for one person but less well for another, or may cause stronger side effects in some people. Genetics is only one part of the picture, and age, other health conditions, and other medicines also play a role.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences shape the way people respond to medications. By studying connections between genes and drugs, it helps explain why the same treatment may work differently from one person to another. For many medicines, genes influence both how the body processes a drug and how strongly it works. This information can support more informed, more individualized treatment decisions. More on this topic is available in the LearnHub.
Drugs influenced by the PADI3 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding how medicines are chosen or how well they work. If you have concerns about side effects, poor response to a treatment, or questions about how your medicines fit with your overall health, it is best to talk with your doctor or pharmacist.
History
PADI3 entered the medical literature through research on hair shaft conditions rather than through a major public story. In recent decades, awareness of this gene’s role has grown as scientists studying inherited hair differences linked PADI3 variants to uncombable hair syndrome. Initially understood only through visible traits, later recognized as tied to a specific gene, this condition became clearer as genetic testing improved. From these first observations, research expanded steadily to confirm PADI3 in affected families and to separate it from other causes of unusual hair texture. The way this gene was viewed has shifted over time, moving from a niche research finding to a recognized part of the genetics of hair disorders.