Patients with ichthyosis, follicular atrophoderma, hypotrichosis, and hypohidrosis present a normal stature, diffuse congenital ichthyosis, patchy follicular atrophoderma, generalized and diffuse non-scarring hypotrichosis, and marked hypohidrosis. Steroid sulfatase activity is normal. Electron microscopic studies of ichthyotic skin do not show any specific abnormality. Subjects with ichthyosis, follicular atrophoderma, hypotrichosis, and hypohidrosis are usually reminiscent of Bazex syndrome in which ichthyosis is not a component.

Autosomal recessive ichthyosis, follicular atrophoderma, hypotrichosis, and hypohidrosis is caused by mutations in the suppression of tumorigenicity 14 (ST14) gene. ST14 is located on the long arm of chromosome 11 and encodes for the matriptase protein, which is a type II transmembrane serine protease. The protein is expressed specifically in terminally differentiating keratinocytes, and in matrix, precortex, and cortex cells, and shaft of the anagen hair, where it exists as a cell surface glycoprotein. Matriptase has been shown to exhibit trypsin-like activity as defined by cleavage of synthetic substrates with Arg or Lys as the P1 site. One of the functions of matriptase, however, is the activation of hepatocyte growth factor, and urokinase plasminogen activator, thus acting as an activator for epithelial growth factors.