[The Clark-Howel-Evans-McConnell syndrome. Observations in one family over 5 generations].

The Clarke-Howel-Evans-McConnell syndrome is a rare hereditary disease characterized by palmoplantar keratoses, squamous cell carcinoma of the esophagus and oral leukoplakia. According to a new classification recently proposed by Stevens and colleagues, the syndrome can also be classified as palmoplantar ectodermal dysplasia type III. We report a family from the Black Forest region of Germany afflicted with the syndrome. The family was traced through five generation. 27 of 46 family members showed tylotic skin changes. In addition, 8 patients showed oral leukoplakia and 5 died from squamous cell carcinoma of the esophagus. Using screening examinations, early changes of the esophageal mucosa could be detected. The responsible gene has been mapped in the family. It is located at 17q23-qter, telomeric to the keratin II gene cluster. Therefore a defect in one of the well known keratin genes can be excluded as a cause of the syndrome.