Hair morphology includes aspects of hair texture such as thickness or shape. In terms of shape, hair is often classified as being either straight, curly, or wavy.
In twins of European ancestry, in a broad sense hair curliness is estimated as having a heritability of 85-95%.[PMID 19803779]
SNPs that may affect hair curliness include:
- rs11803731; one of several in the TCHH gene
- rs17646946; near the TCHH gene
- rs7349332; in the WNT10A gene