Epidermal transglutaminase in the ichthyoses.

Membrane-bound transglutaminase (TGm) is responsible for the cross-linking of proteins to form the cornified envelope. Since abnormalities have been reported in the envelope in certain ichthyoses, we have carried out a survey of TGm concentrations in scales from these disorders. Surprisingly, a striking and specific increase in enzyme activity was found in patients with non-erythrodermic autosomal recessive lamellar ichthyosis. It is not clear how this increase is related to the underlying recessive mutation.