1. ¹Department de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
2. ²Servei de Dermatologia, Hospital del Mar, Barcelona, Spain
3. ³Hospital de Sant Pau, Barcelona, Spain
4. ⁴Departamento de Anatomía e Histología, Universidad de Zaragoza, Barcelona, Spain
5. ⁵Universitat Autònoma de Barcelona, Barcelona, Spain
6. ⁶Unitat de Biologia Cel.lular i Molecular, Institut Municipal d'Investigació Mèdica, Barcelona, Spain

Correspondence: Dr Francisco X. Real, Unitat de Biologia Cel.lular i Molecular, Institut Municipal d'Investigació Mèdica, Carrer del Dr Aiguader 80, E-08003 Barcelona, Spain. E-mail: preal@imim.es

⁷These authors contributed equally to this work

Received 20 September 2006; Revised 14 November 2006; Accepted 16 November 2006; Published online 25 January 2007.

Abstract

Epidermal nevi (EN) are benign lesions presenting at birth or in childhood. Based on the occurrence of fibroblast growth factor receptor 3 (FGFR3) mutations in seborrheic keratosis and urothelial carcinomas (UC), and the identification of two young patients with EN and UC, we hypothesized that mutations might occur in EN. The R248C mutation was found in 6/23 (26.1%) EN but it was absent from unaffected skin. In two patients with EN and UC, both lesions were FGFR3 wild type. Our findings indicate that: (1) FGFR3 mutations occur in mosaicism and can cause EN and (2) other genes are involved in EN.