Scientists home in on genetic causes of uncombable hair syndrome

Mutations in a gene called PADI3 appear to be the most common cause of a rare condition that makes hair stick out at right angles to the scalp

By Clare Wilson

Locklan Samples, a boy with uncombable hair syndrome from Roswell, Georgia

uncombable_locks/Instagr​am

If you see a child with frizzy blond hair that sticks out at right angles to their scalp, they might just have uncombable hair syndrome. A new study has shed more light on this rare condition, which can be caused by several mutations that affect the shape of people’s hair shafts.

The syndrome, which tends to reduce and even disappear by adulthood, is more noticeable in children who are white with pale blonde hair and can cause affected children to be bullied, says Buket Basmanav at the University of Bonn in Germany. “We have been able to offer some explanation for hair that has always been very much attention-drawing.”

Uncombable hair syndrome, also known as spun-glass hair syndrome, was known to be caused by hairs on the head forming with a distorted cross section, instead of the usual circular or oval shape. In 2016, Basmanav and her colleagues identified variants of three genes in 11 children that can cause the unusual hair.

The condition is inherited in a way that means both parents must carry one gene variant, although they aren’t themselves affected – which means families can be mystified as to why their child has hair that literally can’t be combed flat.

The publicity from the initial study caused the team to be contacted by more people who either had affected children or said their hair had been like this when they were younger. It isn’t known why the hair calms down as people get older.

In the latest study, the team studied a larger set of 107 affected individuals and identified a genetic cause in 80 people. In 76 of these people, mutations in a gene called PADI3 were responsible. PADI3 encodes an enzyme that helps to produce trichohyalin, which is one of the main proteins of hair, along with keratin.

In the future, people who suspect their child has uncombable hair syndrome may be able to get this confirmed with a genetic test, says Basmanav. This would provide reassurance that the child doesn’t have a serious medical condition, and that their hair will become more controllable with age.

Journal reference: JAMA Dermatology, DOI: 10.1001/jamadermatol.2022.2319