rs17646946

A SNP in the TCHHL1 gene on chromosome 1. Its most notable genotype is A;A: straighter curl

Gene
TCHHL1
Location
Chr 1152,090,291 (GRCh38)
Highest magnitude
2.5Worth knowing
Tested on
23andMe, AncestryDNA
Minor allele frequency
14%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. A;AMost notableNot ratedstraighter curlWorth knowing · 2.52% of people
  2. G;GNot ratedNo summary available.Typical · 0.079% of people

On SNPedia: (A;A), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Frequency

Share of each genotype in 10 HapMap populations.

  • AverageA;A 2% G;G 79%
  • European ancestry (Utah)A;A 5% G;G 61%
  • Han Chinese (Beijing)A;A 0% G;G 99%
  • Japanese (Tokyo)A;A 0% G;G 99%
  • Yoruba (Nigeria)A;A <1% G;G 90%
  • African ancestry (Southwest US)A;A 2% G;G 68%
  • Gujarati IndianA;A 0% G;G 84%
  • Luhya (Kenya)A;A 2% G;G 74%
  • Mexican ancestry (Los Angeles)A;A 2% G;G 78%
  • Maasai (Kenya)A;A 5% G;G 70%
  • TuscanA;A 5% G;G 65%

Notes

From SNPedia

Notes

rs17646946 is a SNP on chromosome 1 that is apparently part of the trichohyalin-like 1 TCHHL1 gene. Trichohyalin is a protein found in hair follicle roots. In an interesting example of people-powered research, this SNP and one other were reported to be associated with hair curliness. Source: hair curl rs17646946 and rs7349332. source genetic future rs17646946 and hair curl with each A conferring a reduction in curliness of about 0.29 points on a scale from 0 to 5. See also: rs11803731

A;A

curly hair is less likely

Source and license

Adapted from rs17646946 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.

SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.