Is prenatal diagnosis of congenital ichthyosis possible?

Prenatal diagnosis is available for many of the congenital ichthyoses, if one is suspected, based on family history. Fetal skin biopsy performed at 19 to 21 weeks will demonstrate early development of a thickened stratum corneum, normally not present until 24 weeks. This is useful in lamellar ichthyosis, epidermolytic hyperkeratosis, Sjögren-Larsson syndrome, and harlequin fetus. Lamellar ichthyosis may also be detected via a transglutaminase activity assay from a fetal skin sample. Epidermolytic hyperkeratosis, known to result from mutations in keratins 1 and 10, can be detected by direct gene sequencing done on chorionic villus sampling in the second trimester. Cultured chorionic villi cells or amniocytes will demonstrate the enzyme deficiency in XLI, Sjögren- Larsson syndrome, and Refsum’s disease. A high ratio of maternal urinary estrogen precursors in a male fetus also suggests the diagnosis of XLI. Trichothiodystrophy can be identified by unscheduled DNA synthesis in cultured amniocytes exposed to ultraviolet light.

Rothnagel JA: Prenatal diagnosis of epidermolytic hyperkeratosis by direct gene sequencing, J Invest Dermatol 102:13–16, 1994.