In the mid 1800s, a rare syndrome appeared for the first time in medical literature. The case was that of Julia Pastrana, the world’s most famous bearded lady. A new study, being published in today’s issue of the American Journal of Human Genetics, reveals molecular cues about the origin and development of this rare condition.
Congenital generalized hypertrichosis (CGH) covers a group of conditions characterized by excessive hair growth all over the body, regardless of age, gender or race. Congenital generalized hypertrichosis terminalis (CGHT) with gingival hypertrophy is a subgroup of CGH associated with an excess of dark hair, enlarged gums and distorted facial features, as was the case with Julia Pastrana.
The study, performed by scientists from the Chinese Academy of Medical Sciences, discovered the underlying cause for CGHT, with or without gingival hyperplasia. High resolution genetic analyses were conducted on several members of three Chinese families with CGHT, and an individual with sporadic CGHT with gingival hyperplasia. The researchers mapped the location of the gene on a chromosome, and found that genetic defects on chromosome 17q24.2-q24.3 were responsible for CGHT, regardless of whether or not the patient also exhibited gingival hyperplasia.
The three families with CGHT that were studied showed different DNA deletions on the identified chromosome region. In the individual with a sporadic case of CGHT, the identified chromosome region had a DNA duplication. These mutations affected four to eight genes in the identified region, establishing CGHT as a genomic disorder.
Sun et al. (2009). Report: Copy-Number Mutations on Chromosome 17q24.2-q24.3 in Congenital
Generalized Hypertrichosis Terminalis with or without Gingival Hyperplasia American Journal of Human Genetics, 84 (6)