New research has shed light on the genetic underpinnings of a bizarre syndrome - first exhibited by a mid-1800s bearded lady - that has fascinated the public for centuries.
The case of bearded Mexican-born woman Julia Pastrana in the mid-1800s was the condition's first appearance in medical literature, noted Chinese researchers whose study was published in the American Journal of Human Genetics.
Researchers uncovered the specific genetic mutations that underlie congenital generalised hypertrichosis (CGH), a condition that spurs excessive hair growth over the entire human body.
They performed a sophisticated, high-resolution genetic analysis of several members of three Chinese families with congenital generalized hypertrichosis terminalis (CGHT), a subgroup of the condition, as well as an individual with a sporadic case of CGHT with gingival hyperplasia, an overgrowth of gum tissues.
What causes the 'bearded' look
CGHT is associated with "universal overgrowth of darkly pigmented hairs, enlarged gums and a distortion of facial features," a phenomenon evidenced by Pastrana.
The condition has been almost impossible to study because of its rarity, but senior study author Xue Zhang and colleagues were able to perform extensive genetic analysis on three Chinese families with the genetic disorder.
"Although it has long been believed that most people with CGH have some kind of genetic defect, the specific genetic mutations that underlie CGHT ... had not been discovered until now," said Xue of the Chinese Academy of Medical Sciences and the Peking Union Medical College in Beijing.
The research team mapped the genetic locus of the syndrome and found the DNA deletions associated with it. "Our work clearly establishes CGHT as a genomic disorder," said Xue, adding however that more studies were needed to further uncover the exact molecular mechanisms that define the disorder. – (Sapa, May 2009)