%0 Journal Article
%T Systemic epidermal nevus with involvement of the oral mucosa due to FGFR3 mutation
%A Anette Bygum
%A Christina R Fagerberg
%A Ole J Clemmensen
%A Britta Fiebig
%A Christian Hafner
%J BMC Medical Genetics
%D 2011
%I BioMed Central
%R 10.1186/1471-2350-12-79
%X We report a female patient with a systemic keratinocytic nevus also involving the oral mucosa. Molecular genetic analysis revealed a mosaicism of the FGFR3 hotspot mutation R248C in the EN lesions of the skin and of the oral mucosa. The detection of the R248C mutation in a proportion of blood leukocytes and a slight scoliosis suggest an EN syndrome.Our results show that activating FGFR3 mutations can also affect the oral mucosa and that extracutaneous manifestations of EN syndrome can be subtle. We highlight the theoretical risk of the patient having an offspring with thanatophoric dysplasia as gonadal mosaicism for the R248C mutation cannot be excluded.Epidermal nevi (EN) are benign hamartomas of the skin arising from the embryonic ectoderm. Depending on the involved components of the epidermis, EN are further divided into organoid and non-organoid (keratinocytic) types [1]. They are usually present at birth or develop during the first years of life, and their incidence is estimated to be 1-3 per 1000 live births [2]. Keratinocytic nevi typically follow the lines of Blaschko. Systemic keratinocytic nevi are characterized by an extensive involvement of large skin areas and may be associated with skeletal, cerebral or ocular abnormalities, resulting in various types of EN syndromes [1,2]. EN represent genetic mosaicism of the skin and activating FGFR3 (Fibroblast Growth Factor Receptor 3) and PIK3CA point mutations have recently been identified in keratinocytic nevi [3-6].We report a patient with systemic EN associated with a slight scoliosis, who displayed mosaicism of the R248C FGFR3 mutation in epidermis, oral mucosa and blood leukocytes.A 17-year old girl was referred with widespread EN (Figure 1 A+B). She was otherwise healthy apart from a tendency to back pain. Her parents recalled the first appearance of the EN when she was 4 months old. The EN initially presented as hyperpigmented linear streaks which gradually increased in size and thickness, becoming more e
%U http://www.biomedcentral.com/1471-2350/12/79