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Is hair texture determined by genetics?
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Traits

Is hair texture determined by genetics?

Hair texture and thickness are primarily determined by genetic factors, though environmental influences and aging also play significant roles.

Genetic Factors

Genetic factors appear to play a major role in determining hair texture—straight, wavy, or curly—and the thickness of individual strands of hair. Studies suggest that different genes influence hair texture and thickness in people of different ethnic backgrounds:

  • EDAR and FGFR2: Normal variations (polymorphisms) in these two genes have been associated with differences in hair thickness in Asian populations.
  • TCHH: A polymorphism in this gene appears to be related to differences in hair texture in people of northern European ancestry.

It is likely that many additional genes contribute to hair texture and thickness in various populations.

Genetic Syndromes

Several genetic syndromes are characterized by unusual hair texture. These syndromes are caused by variants in genes that play roles in hair structure and stability, including genes associated with specialized cell structures called desmosomes that hold hair cells together, proteins called keratins that provide strength and resilience to hair strands, and chemical signaling pathways involving a molecule called lysophosphatidic acid (LPA), which promotes hair growth. Genetic syndromes that feature altered hair texture include:

  • Autosomal recessive hypotrichosis (caused by variants in the DSG4, LIPH, or LPAR6 gene)
  • Keratoderma with woolly hair (caused by variants in the JUP, DSP, DSC2, or KANK2 gene)
  • Monilethrix (caused by variants in the DSG4, KRT81, KRT83, or KRT86 gene)
  • Uncombable hair syndrome (caused by variants in the PADI3, TCHH, or TGM3 gene)

Researchers speculate that the genes associated with these disorders probably also contribute to normal variations in hair texture and thickness.

Non-Genetic Influences

Factors other than genetics can also influence hair texture and thickness. Hormones, certain medications, and chemicals such as hair relaxers or perms can alter the characteristics of a person’s hair. These changes can be temporary or permanent. Hair texture and thickness can also change with age.

Frequently Asked Questions

Yes, while genetics primarily determine your hair texture, environmental factors, hormonal changes, and aging can cause noticeable shifts. For example, hair can become finer, coarser, or change its curl pattern due to hormonal fluctuations during puberty, pregnancy, or menopause, or simply as part of the natural aging process.
Beyond genetics, factors like diet, hydration, chemical treatments (coloring, perms, relaxers), heat styling, and even certain medications can alter your hair's texture. Environmental exposure to sun, wind, and pollution can also impact hair health and appearance, making it feel rougher or drier.
If you or a family member have an unusual hair texture that is also accompanied by other health concerns, it's best to consult a dermatologist or a genetic counselor. They can evaluate your symptoms, family history, and potentially recommend genetic testing to identify if a specific genetic syndrome, like monilethrix or uncombable hair syndrome, is the cause.
Yes, researchers have identified several genes linked to common hair textures. For instance, variations in the TCHH gene are associated with differences in hair texture in people of northern European ancestry, while EDAR and FGFR2 genes have been linked to hair thickness in Asian populations. It's likely that many other genes also contribute to the wide range of normal hair textures seen across different populations.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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