The flurry of emails about frizzy hair began in 2016.
Human geneticist Regina Betz of Bonn University Hospital in Germany and her team had just linked three genes for a rare disorder with striking symptoms– Silver, sequined, spun glass hair that just doesn’t go flat. Called uncombable hair syndrome, patients can have dry, shiny locks that separate from the scalp like a cloud of dandelion fuzz. Only about 100 cases had been reported.
But after the study, which looked at 18 cases, people from all over the world reached out. “They said, ‘Oh, I have a child like that,’ or ‘Oh, I looked exactly like this as a child,'” says study co-author Buket Basmanav, a geneticist also at Bonn University Hospital. “Regina said, ‘Send us her samples.'”
Now the team has analyzed DNA samples from 107 people with uncombed hair syndrome. Single-gene variants accounted for 71 percent of cases, researchers reported Aug. 31 in JAMA Dermatology.
the Gen, PADI3, encodes an enzyme involved in the formation of the hair shaft. mutations in PADI3 can interrupt the process, modifying the structure of the hair. In people with the syndrome, the hair shaft is ribbed, like “a paper straw that has collapsed in on itself,” says Gillian Westgate, a hair biologist at the University of Bradford in England who was not involved in the study.
Basmanav and his colleagues also linked nearly 4 percent of cases to variants of TGM3 either TCHH, the other two hair shaft genes that the team had previously studied. Nearly a quarter of the cases in the new study remain genetically unexplained.
The work could help doctors diagnose the disorder, which often improves with age and is often unrelated to health problems. Genetically testing children with unusually tall locks could ease the minds of parents worried that their child’s hairstyle is a sign of something more serious, says Westgate.
Basmanav adds that a diagnosis of uncombable hair syndrome can be a relief because “we don’t expect any additional symptoms to appear.”