At first sight or second glance: clinical presentation of mosaic manifestations of autosomal dominant skin disorders - a case series.
BACKGROUND
Several autosomal dominant disorders may manifest in mosaic patterns with cutaneous involvement. Genomic mosaicism results from postzygotic autosomal mutations, giving rise to clonal proliferation of two genetically distinct cell groups, which clinically present as lesions following the lines of Blaschko.


OBJECTIVE
To increase the awareness of the clinical variability of mosaic manifestations in autosomal dominant skin disorders in order to avoid delayed diagnosis.


METHODS
Clinicopathologic correlation in a case series including three patients with mosaic manifestations of different autosomal dominant skin diseases.


RESULTS
Here, we describe a patient with type 1 segmental mosaicism of epidermolytic ichthyosis (case 1) and two patients with either type 1 (case 2) or type 2 (case 3) segmental neurofibromatosis 1 (NF1).


CONCLUSIONS
Dermatologists should be familiar with mosaic manifestations of autosomal dominant skin diseases to ensure appropriate guidance of the affected patient. Genetic counselling is mandatory as even limited forms of mosaicism may involve the patient's germline with a moderately increased risk to transmit the mutation to their offspring, resulting in a more severe, generalized form of the respective disease.
Department of Dermatology, Venerology, and Allergology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
F
F
Toberer
Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany.
R
R
Happle
Department of Dermatology, Venerology, and Allergology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
R
R
Schneiderbauer
Department of Pathology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
I
I
Hausser
Department of Dermatology, Venerology, and Allergology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
V
V
Kröhl
Department of Dermatology, Venerology, and Allergology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
A
A
Epple
Institute of Human Genetics, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
U
U
Moog
Department of Dermatology, Venerology, and Allergology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
A H
AH
Enk
Department of Dermatology, Venerology, and Allergology, University Medical Center, Ruprecht-Karls-University, Heidelberg, Germany.
A S
AS
Lonsdorf
D000293:Adolescent; D002648:Child; D005260:Female; D005799:Genes, Dominant; D006801:Humans; D008297:Male; D009030:Mosaicism; D012871:Skin Diseases / Q000235:genetics / Q000473:pathology*