X-Linked Ichthyosis

In the epidermis from 4 cases of X-linked ichthyosis, granular cells contained a large number of keratohyalin granules of irregular surface, the largest ones having a spongy appearance. Keratinosomes were normal both in number and degree of extrusion. Corneal cells were linked by desmosomal discs up to the most superficial layers. The abnormal persistence of desmosomal discs may be a consequence of a decrease in the activity of acid hydrolases within the keratinosomes. In corneal cells there were a great number of melanosomes with normal appearance which may be responsible for scale pigmentation. Such increased number may be attributed to a deficiency in melanosome spontaneous degradation, rather than to an increased formation.