Hair & Skin

Hair curl pattern

Hair curl pattern depends on the shape and size of the hair follicle and on cross-links inside the hair shaft.

Variants in TCHH (trichohyalin), EDAR, and other hair structure genes have been linked to differences in hair curl across populations.

This result reflects research-level variation in hair biology and is not direct observation of curl pattern.

Humidity, hair length, hair care products, age, and damage all strongly affect how hair curl looks day to day.

3 SNPs

5 Studies

Oct 14, 2026

DEMO REPORT

Your Analysis

Genetic Tendency

Based on your genetic markers, your tendency toward this trait is shown below

Your Result

Less likely to have straighter hair

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Confidence Score

Very high

This score indicates how strongly your genetics predispose you to this trait based on 3/3 SNPs detected.

Trait Influence Breakdown

Genetic

85%

Environment

15%

Scientific Evidence

Understanding the Data

SNP: A specific genetic marker relevant to this trait (e.g., rs2588978)
Genotype: Your genetic makeup at the given SNP location (e.g., CC)
Variant allele: The alternative DNA sequence at the SNP site

Variant allele frequency: Percentage of population carrying this variant
Variant found: Whether the variant was detected in your DNA file

Variant Detected

TCHHL1 GeneCards

This gene belongs to the S100 fused-type protein (SFTP) gene family, and is located in a cluster of SFTP genes on chromosome 1q21. Several members of this family have been implicated in the development of complex skin disorders. This gene is evolutionarily conserved; its expression appears to be hair-specific and spatially restricted within the distal inner root sheath of the hair follicle. It thus may have an important role in hair morphogenesis. [provided by RefSeq, Aug 2013]

Genomic Location

Chr 1 Start: 152,084,141 End: 152,089,064 Build: HG19

5' end 3' end

Associated SNPs

1 / 1 detected

SNP	Genotype	Ref. Allele	Variant Allele	Frequency	Status
rs17646946	A G	G	A	11.32%	Detected
Your Genotype AG Reference Allele G Variant Allele A Population Frequency 11.32% Variant Status Variant Detected Database Link NCBI dbSNP

These are the genetic markers (SNPs) analyzed for this trait. Variations detected in your genome are listed under the "Genotype" column. SNPs showing "--" were not identified in your DNA file.

SNP	Chromosome	Genotype	Variant Allele	Frequency
rs17646946	1	AG	A	11.32%

DNA Genics reports genotypes based on the 'positive' strand of the human genome reference sequence (build 37/HG19). Other companies may use the opposite strand, so genotypes may need conversion for comparison.

The following peer-reviewed scientific studies support the genetic associations analyzed in this report.

Web-based, participant-driven studies yield novel genetic associations for common traits

Evidence

06/24/2010

PLoS Genet

Authors: Eriksson N, Macpherson JM, Tung JY, Hon LS, Naughton B, Saxonov S, Avey L, Wojcicki A, Pe&#39, er I, Mountain J

9,126 individuals (european ancestry)

Common variants in the trichohyalin gene are associated with straight hair in Europeans

Evidence

2009 Nov

Am J Hum Genet

Authors: Medland SE, Nyholt DR, Painter JN, McEvoy BP, McRae AF, Zhu G, Gordon SD, Ferreira MA, Wright MJ, Henders AK, Campbell MJ, Duffy DL, Hansell NK, Macgregor S, Slutske WS, Heath AC, Montgomery GW, Martin NG

20,985 individuals (european ancestry)

Meta-analysis of genome-wide association studies identifies 8 novel loci involved in shape variation of human head hair

Evidence

02/01/2018

Hum Mol Genet

Authors: Liu F, Chen Y, Zhu G, Hysi PG, Wu S, Adhikari K, Breslin K, Pospiech E, Hamer MA, Peng F, Muralidharan C, Acuna-Alonzo V, Canizales-Quinteros S, Bedoya G, Gallo C, Poletti G, Rothhammer F, Bortolini MC, Gonzalez-Jose R, Zeng C, Xu S, Jin L, Uitterlinden AG, Ikram MA, van Duijn CM, Nijsten T, Walsh S, Branicki W, Wang S, Ruiz-Linares A, Spector TD, Martin NG, Medland SE, Kayser M

16,763 individuals (european ancestry)

Evaluation of the predictive capacity of DNA variants associated with straight hair in Europeans

Evidence

2015 Nov

Authors: Pośpiech E, Karłowska-Pik J, Marcińska M, Abidi S, Andersen JD, Berge MVD, Carracedo Á, Eduardoff M, Freire-Aradas A, Morling N, Sijen T, Skowron M, Söchtig J, Syndercombe-Court D, Weiler N, Schneider PM, Ballard D, Børsting C, Parson W, Phillips C, Branicki W,

The biology and genetics of curly hair

Evidence

2017 Jun

Authors: Westgate GE, Ginger RS, Green MR

Important Medical Disclaimer

This report is intended for educational and informational purposes only. It is not intended to provide medical advice or be used solely by the customer in the diagnosis, cure, mitigation, treatment, or prevention of any disease or health condition. If you have serious medical conditions, including but not limited to weight-related issues, diabetes, or heart disease, you should not make changes to your diet or exercise routine without consulting your healthcare provider. Under no circumstances should you modify your medication or medical care without professional medical guidance.

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