Today, it is difficult to imagine surviving the sweltering heat of summer without a decent cooling system. Inadequate production of sweat, nature's built-in coolant, is just one of the maladies endured by individuals who inherit a rare disorder called hypohidrotic ectodermal dysplasia. Affected children often have very little hair and usually require dentures during early childhood to help them eat normally.
First described by Charles Darwin, it has taken over a century for the genetic basis of this affliction to begin to fall into place. On the heels of the discovery of a mutated X-chromosome gene, researchers at Oregon Health Sciences University (OHSU) and the Baylor College of Medicine have now found another aberrant gene that produces identical symptoms, this one located on chromosome 2. The discovery of a second gene for this disorder improves the prospects for genetic diagnosis, and new insights into gene function may help in developing future therapies.
Dr. Jonathan Zonana from OHSU was a member of the international research team that tracked down the X-chromosome gene, and he is also an integral part of the group that identified the gene on chromosome 2. Zonana, along with Dr. Alex Monreal and colleagues, report their latest discovery in the August issue of Nature Genetics. The research was supported in part by the National Institutes of Health.
The hypohidrotic ectodermal dysplasia story dates back to 1875, when Darwin
described a peculiar disorder that appeared in each generation of one family's
male members. The mysterious condition became apparent in the very young,
manifesting itself with poorly developed teeth, sparse hair on the head and
body, and excessively dry skin due to underdeveloped sweat glands. These
characteristics were the origin of the disorder's tongue-twister
name--"hypohidrotic" referring to low levels of perspiration, and "ectodermal
dysplasia" meaning abnormal development of certain tissues derived from
Contact: Wayne Little
NIH/National Institute of Dental and Craniofacial Research