Yu Zhenhuan, who calls himself King Kong, is a modern equivalent of the bearded ladies, with his own media presence (Image: Sinopix/Rex Features) Portrait of Julia Pastrana, the celebrated bearded lady of the 1850s who died in 1860 from childbirth complications (Image: Photo by Alinari/ ex Features) Anna Gonlt, bearded lady, at Barnum Circus, 1880 (Image: Roger-Viollet/Rex Features)


A 31-year-old Chinese man whose body is 96 per cent coated in hair has an extra chunk of DNA that could explain his condition – called congenital generalized hypertrichosis terminalis (CGHT).

A new study of the patient known as “KK” – one of the world’s hairiest men – and three families with a history of CGHT suggests that the disease is caused by vast genomic changes on chromosome 17.

CGHT is exceedingly rare, with fewer than 100 cases documented in news reports and the scientific literature, says Xue Zhang, a geneticist at Peking Union Medical College in Beijing, who led the new study.

The disease is one of at least several forms of hypertrichosis – all characterised by overgrowth of hair. One of the earliest recorded cases involved a Mexican Indian woman, Julia Pastrana, who toured Europe in the 1850s and 60s, before dying due to complications from childbirth.

Disturbed DNA

To find the genetic changes responsible for CGHT, Zhang’s team first scanned the genomes of 16 people with the disease and their unaffected relatives, looking for obvious differences.

A region on chromosome 17 jumped out, and after further study, Zhang’s team showed that family members with CGHT were missing between 500,000 and 900,000 DNA letters on that chromosome. Patient KK, on the other hand, had 1.4 million extra nucleotides at the same place on the genome.

Exactly how these changes cause the disease is unclear, says Zhang. One of the several genes in this region, MAP2K6, could be involved in hair growth. But mice missing lacking this gene have normal hair, and a 12-year-old girl missing this gene shows no signs of CGHT. More likely, the changes on chromosome 17 affect the expression of distant genes, Zhang’s team suggests.

Far-reaching effects?

Large deletions or insertions of DNA can interfere with the relationship between genes and the non-coding sequences that control their activity. So the gene or genes truly responsible for CGHT could be millions of letters away from the changes that Zhang’s team found.

“It’s not going to be trivial for them to sort this out,” says Pragna Patel, a medical geneticist at the University of Southern California, who was not involved in the study.

Yet finding the true cause of CGHT will help scientists understand and potentially treat, not just a rare disease, but other conditions characterised by excessive hair growth or loss, Patel says. “I think beyond helping these individual patients, clearly there’s a large segment of the population that would be interested in that.”

Journal reference: American Journal of Human Genetics (DOI: 10.1016/j.ajhg.2009.04.018)