Researchers have linked variants in three genes to 'uncombable hair syndrome,' as they report in the American Journal of Human Genetics.
The rare syndrome, which affects young children, is marked by dry, frizzy, and, typically, fair hair that can't be combed flat. By adulthood, though, the hair of people with the syndrome becomes more manageable.
The University of Bonn's Regina Betz and Michel Simon from the University of Toulouse sequenced the exomes nearly a dozen children affected by the syndrome to home in on changes to three genes, PADI3, TGM3, and TCHH. PADI3 and TGM3, the researchers note, are involved in posttranslational protein modifications while TCHH is involved in hair shaft formation.
In a series of cell culture experiments, Betz, Simon, and their colleagues found that alterations to these genes affect the functions of the proteins they encode as well as the structure and stability of hair. A mouse models with either defective PADI3 or TGM3 exhibited a fur phenotype similar to that seen in affected kids, the researchers add.
"From the mutations found, a huge amount can be learned about the mechanisms involved in forming healthy hair, and why disorders sometimes occur," Betz says in a statement. "At the same time, we can now secure the clinical diagnosis of 'uncombable hair' with molecular genetic methods."