Mosaic expression of hypohidrotic ectodermal dysplasia in an isolated affected female child.

BACKGROUND

Hypohidrotic ectodermal dysplasia (HED) is characterized by hypotrichosis, hypodontia, onychodysplasia and, as the most striking feature, hypohidrosis. The X-linked recessive form of HED, also known as Christ-Siemens-Touraine syndrome, is the most frequent and widely documented form. A clinically identical autosomal recessive form of HED has also been described. Because of the X-linked mode of inheritance, nearly all observations have concerned pedigrees of predominantly male affected patients. We present a rare isolated affected female child with a mosaic expression of HED. We attempted to assess the mode of inheritance in our case.

OBSERVATIONS: We documented the characteristic clinical appearance in our proband, as well as the scanning electron microscopic findings regarding the hair. The starch-iodine test results in this patient revealed the clinical expression of HED in a mosaic fashion, running along the Blaschko lines.

CONCLUSIONS

The starch-iodine test results proved to be useful in the assessment of carriers of X-linked HED, and our proband was considered to an isolated affected female with a mosaic expression of HED.