Taylor, an adorable 18-month-old toddler from the Chicago suburbs, will probably never experience what its like to have the sleek, shiny hair that modern beauty standards idealize, but that’s OK, because she is truly one in a million. Scratch that – more like one in 76 million.
As first reported by Buzzfeed News, Taylor McGowan is one of the very small handful of people diagnosed with uncombable hair syndrome (UHS), an incredibly rare inherited condition that is caused by mutations in one or more of three genes that are involved in hair shaft formation.
Also known as ‘spun glass hair syndrome’, ‘pili trianguli et canaliculi,’ or ‘cheveux incoiffables’, UHS has been officially recognized as a hair disorder since in 1973, yet the distinctive outward phenotype was not linked to an underlying genotype until 2016. That year, a study led by researchers from the University of Bonn, Germany, established that the unusually fine, frizzy, and wiry hair texture arises from homozygous function-altering variations of the PADI3, TGM3, or TCHH sequences; meaning it is a recessive condition that only presents when individuals receive mutant gene copies from both parent.
The group’s data came from whole-genome sequencing of 11 people with UHS. To date, there have been 101 (including Taylor) reported cases.
Most individuals with diagnosed UHS, including Taylor, carry variations in PADI3, which encodes an enzyme called peptidylarginine deiminase type III. This catalytic protein, expressed in the hair follicle, modifies the electrical charge on hair structural proteins so that they can be knitted together into the shaft. When the enzyme isn’t working properly, the shafts take on a wrinkled, triangular shape that prevents them from lying flat on top of one another. UHS hair is often silvery, blonde, or strawberry in color and may also grow at a slower-than-normal rate.
UHS hair texture often becomes more manageable as the individual ages, but even in those cases, it remains delicate and at least somewhat unruly for life.