title: An epidermal nevus syndrome with cerebral involvement caused by a mosaic FGFR3 mutation.
abstract: A 5-year-old Mexican girl had a bilateral, systematized epidermal nevus of a non-epidermolytic, non-organoid type covering large parts of her body with the exception of the scalp. Clinically, this nevus was of a soft, velvety type showing affinity to the large body folds. Histopathological examination revealed orthohyperkeratosis and papillomatosis without granular degeneration and without any abnormality of adnexal structures. During infancy she developed seizures, and subsequently a delayed mental development was noted. Computer tomography of the brain revealed cortical and subcortical atrophy, a subdural hygroma in the left frontoparietotemporal region, and hypoplasia of corpus callosum. Molecular analysis of a biopsy specimen obtained from the epidermal nevus revealed a heterozygous R248C hotspot mutation in FGFR3, whereas in normal skin the FGFR3 wild-type allele was exclusively found. The R248C mutation was also present in DNA extracted from blood leukocytes. Because FGFR3 is involved in the development of the central nervous system, the clinical and genetic findings of this case indicate a widespread mosaicism of the FGFR3 mutation. This unusual mosaic phenotype may represent a distinct entity within the group of epidermal nevus syndromes.
authors.affiliation: Instituto Dermatológico de Jalisco "Dr. José Barba Rubio", Guadalajara, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: García-Vargas
authors.forename: Christian
authors.initials: C
authors.lastname: Hafner
authors.forename: Adriana G
authors.initials: AG
authors.lastname: Pérez-Rodríguez
authors.forename: L Ximena
authors.initials: LX
authors.lastname: Rodríguez-Rojas
authors.forename: Pedro
authors.initials: P
authors.lastname: González-Esqueda
authors.forename: Robert
authors.initials: R
authors.lastname: Stoehr
authors.forename: Mercedes
authors.initials: M
authors.lastname: Hernández-Torres
authors.forename: Rudolf
authors.initials: R
authors.lastname: Happle
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D054022:Cerebrum / Q000002:abnormalities*; D002675:Child, Preschool; D004817:Epidermis / Q000002:abnormalities; D004827:Epilepsy / Q000235:genetics; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D009030:Mosaicism; D009154:Mutation; D009508:Nevus, Pigmented / Q000235:genetics*; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000235:genetics*; D012878:Skin Neoplasms / Q000235:genetics*; D013577:Syndrome
chemical_list: C496365:FGFR3 protein, human; D051498:Receptor, Fibroblast Growth Factor, Type 3