Mosaic epidermolytic ichthyosis - case report

Abstract

Epidermolytic ichthyosis is a rare autosomal dominant disease that manifests at birth with fragile blisters and erosions that evolve into hyperkeratotic lesions associated or not with erythroderma. When the disease is associated with a mutation in cytokeratin 1, it may be related to hyperkeratosis of palms and soles, but this is not usually found when cytokeratin 10 is mutated. The disease can present in a mosaic form, due to post zygotic mutation of the gene involved, constituting an individual formed by two populations of genetically distinct cells - one carrier of the mutation and the other without it. We report a case of mosaic epidermolytic ichthyosis diagnosed in a female patient.

Extensive Post-zygotic Mosaicism of KRT1 or KRT10 Mutation Mimicking Classical Epider­molytic Ichthyosis

“…Molecular proof of mosaicism in EI has been reported previously in 2 individuals (6, 7). The neonatal inflammatory phase was probably present in 2 cases, but was mentioned for one only of them (7). One had limited lesions, whereas the other had a very extensive distribution similar to our female patient (6).…”

“…The percentage of KRT1 or KRT10 de novo mutations is very high, from 50% to 75% (2,11). Part of these de novo mutations may correspond to parental mosaic mutations, which are often undetectable using the classical Sanger method, since the mutant allele is present at a low intensity (7). Next-generation deep-sequencing methods offer opportunities to assess mosaicism, including the low-grade and should therefore permit the diagnosis of more cases of mosaicism in the future (13).…”

Congenital unilateral reticulate keratotic papules on the lower extremity

“…Nevoid follicular EHK needs to be differentiated from other nevoid conditions like mosaic EHK, epidermolytic verrucous epidermal nevus (VEN), and nevus comedonicus, all of which can show changes of EHK on histopathology. Mosaic EHK appears as linear verrucous plaques with accentuation of lesions in flexures and around joints with a “corrugated cardboard appearance,” and its biopsy reveals focal epidermolytic hyperkeratosis with skip areas of normal‐appearing epidermis . Epidermolytic VEN usually presents as pigmented warty streaks and plaques since birth whose biopsy shows prominent hyperkeratoses, acanthosis, and papillomatosis with EHK.…”

Coxsackie Eruption Arising in Areas of Epidermolytic Ichthyosis

“…We describe a rare presentation of mosaic EI with coxsackie. EI, also known as epidermolytic hyperkeratosis, is a rare genetic disorder of keratinization due to an autosomal dominant or somatic mutation in keratin 1 or 10 . Somatic mutations result in a mosaic form of the disease that usually manifests as widespread linear plaques following lines of Blaschko .…”