Harlequin ichthyosis: an ultrastructural study.

The clinical, electron microscopic, and freeze-fracture features of the skin of a harlequin fetus are described. Ultrastructural findings included large, concentric lamellar bodies, focal absence of intercellular stratum corneum lipid, and an increase in the size of desmosomes and the number of tight junctions. Although the cause of this genodermatosis is unknown, these features may partially explain the marked thickening of stratum corneum that characterizes this disorder.