RESUMO
<p><b>OBJECTIVE</b>To investigate the clinical features and molecular mechanism of hidrotic ectodermal dysplasia (HED).</p><p><b>METHODS</b>A clinical and gene study was performed for five generations (91 people) in the family of one proband with HED. GJB6 gene detection was performed for 7 patients and 3 normal people in this family.</p><p><b>RESULTS</b>Among the 91 people in this family, there were 17 HED patients, who were manifested as having dysplasia of the fingernails and toenails and sparse or absent hair or body hair. The male patients had a greater degree of sparse hair compared with female patients. In the younger generations, damage to the fingernails and toenails was gradually alleviated. There were patients in each generation, the patient's mother or father definitely had this disease. Both males and females developed this disease, and the inheritance pattern was autosomal dominant inheritance. A heterozygous missense mutation, 31G→A, in GJB6 gene was detected in all patients in this family, but this mutation was not detected in family members without the clinical manifestations of HED.</p><p><b>CONCLUSIONS</b>HED is a hereditary disease with autosomal dominant inheritance and has the clinical features of dysplasia of the fingernails and toenails, hyperkeratosis of palms and soles, and sparse or absent hair or body hair. Male patients have a greater degree of sparse hair. In the younger generations, damage to the fingernails and toenails is gradually alleviated. The missense mutation 31G→A in the GJB6 gene may be one of the molecular mechanisms for HED.</p>