Six male patients with confirmed X-linked hypohidrotic ectodermal dysplasia and their mothers were studied to determine the variation of expressivity in patients and heterozygotes, major problems of the patients, and to find a clue to pathogenesis.
The number of teeth, conic in shape, in patients varied from none to 14. In addition to hypohidrosis and hypotrichosis, dry skin, reduced salivation, hoarseness and hypoplasia of the nipples were common signs. Five patients had frequent respiratory infections.
The mothers lacked more than four permanent teeth, one mother had hypodontia in the deciduous dentition.
The sweat pore counts were low in patients, and lower than normal in the mothers.
All patients carried β-hemolytic streptococci, four of them group A either in nose or pharynx, without symptoms. Immunoglobulin values, including IgA were normal in serum and saliva.
Unexpectedly, serum parathyreoid hormone concentrations both in patients and mothers were low.
The major problem of the families was the risk of hyperpyrexia due to hypohidrosis, but the patients' concern was mostly because of their facial appearance.