Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2020 Mar;182(3):552-563.
doi: 10.1111/bjd.17924. Epub 2019 Jul 18.

Mosaic abnormalities of the skin: review and guidelines from the European Reference Network for rare skin diseases

V A Kinsler  1   2 , O Boccara  3 , S Fraitag  4 , A Torrelo  5 , P Vabres  6   7 , A Diociaiuti  8
Affiliations
Review

Mosaic abnormalities of the skin: review and guidelines from the European Reference Network for rare skin diseases

V A Kinsler et al. Br J Dermatol. 2020 Mar.

Abstract

Background: Cutaneous mosaicism is an area of dermatology in which there has been an explosion of knowledge within the current decade. This has led to fundamental changes in the understanding of the conditions in this field, and to an ongoing paradigm shift in the approach to management of mosaic skin disorders.

Objectives: To lay out the general principles of mosaicism as they are currently understood, summarize the known cutaneous mosaic abnormalities of the skin with associated phenotypic and genotypic information, review the latest trials on targeted therapies and propose guidelines for the general approach to a patient with suspected mosaicism.

Methods: This was a consensus expert review as part of the European Reference Network project (ERN-Skin).

Conclusions: This study provides clinicians with a practical approach to the patient with suspected mosaicism, redefines mosaicism for the modern genetic era, and proposes a new classification system based on genetic mechanism. What's already known about this topic? Cutaneous mosaicism is a complex field of dermatology that encompasses most birthmarks, and many rare syndromes. Some cutaneous patterns are known to be seen in mosaicism. Very few treatment options are available for most mosaic abnormalities of the skin. Recent high-sensitivity genetic techniques have led to an explosion of knowledge about genotype and phenotype in the literature. What does this study add? Expert consensus from the European Reference Network project. Review of knowledge of confirmed mosaic abnormalities of the skin, including cutaneous phenotype, extracutaneous associated features and genotype. Proposed new classification of mosaic abnormalities of the skin by genetic mechanism and therefore inheritance potential. Practical tips on correct sample collection and genetic investigation. Review of trials of targeted therapies. Guidelines for a practical clinical approach to the patient with suspected mosaicism.

PubMed Disclaimer

References

    1. Blaschko A. Die Nervenverteilung in der Haut in ihrer Beziehung zu den Erkrankungen der Haut. In: Bericht erstattet dem VII. Congress der Deutschen Dermatologischen Gesellschaft. Wilhelm Braumüller: Breslau, 1901.
    1. Jackson R. The lines of Blaschko: a review and reconsideration: observations of the cause of certain unusual linear conditions of the skin. Br J Dermatol 1976; 95:349-60.
    1. Happle R. Lethal genes surviving by mosaicism: a possible explanation for sporadic birth defects involving the skin. J Am Acad Dermatol 1987; 16:899-906.
    1. Happle R. Mosaicism in human skin. Understanding the patterns and mechanisms. Arch Dermatol 1993; 129:1460-70.
    1. Poblete-Gutierrez P, Wiederholt T, Konig A et al. Allelic loss underlies type 2 segmental Hailey-Hailey disease, providing molecular confirmation of a novel genetic concept. J Clin Invest 2004; 114:1467-74.