title: Whorled hairless nevus of the scalp, linear hyperpigmentation, and telangiectatic nevi of the lower limbs: a novel variant of the "phacomatosis complex".
abstract: The term "phacomatosis" refers to a growing number of sporadic genetic skin disorders characterized by the combination of two or more different nevi and possibly resulting from non-allelic twin spotting. While phacomatosis pigmentovascularis (PPV) and pigmentokeratotica represent the most common patterns, some patients do not fit with either condition and are temporarily classified as unique phenotypes. We report on an 8-year-old boy with striking right hemihypoplasia, resulting in limb asymmetry and fixed dislocation of right hip. Skin on the affected side showed three distinct nevi: (i) A whorled, hairless nevus of the scalp in close proximity with (ii) epidermal hyperpigmentation following lines of Blaschko on the neck and right upper limb, and (iii) multiple telangiectatic nevi of the right lower limb and hemiscrotum. Didymosis atricho-melanotica was proposed for the combination of adjacent patchy congenital alopecia and linear hyperpigmentation, while phacomatosis atricho-pigmento-vascularis appears to define the entire cutaneous phenotype, thus implying the involvement of three neighboring loci influencing the development of distinct constituents of the skin. Given the striking asymmetry of the observed phenotype, the effect of mosaicism (either genomic or functional) for a mutation in a single gene with pleiotropic action and influenced by the lateralization pattern of early development cannot be excluded.
authors.affiliation: Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Rome, Italy. mcastori@scamilloforlanini.rm.it
authors.forename: Marco
authors.initials: M
authors.lastname: Castori
authors.forename: Oronzo
authors.initials: O
authors.lastname: Scarciolla
authors.forename: Silvia
authors.initials: S
authors.lastname: Morlino
authors.forename: Liborio
authors.initials: L
authors.lastname: Manente
authors.forename: Assunta
authors.initials: A
authors.lastname: Biscaglia
authors.forename: Alberto
authors.initials: A
authors.lastname: Fragasso
authors.forename: Paola
authors.initials: P
authors.lastname: Grammatico
mesh_terms: D002648:Child; D006222:Hamartoma / Q000235:genetics / Q000473:pathology; D006391:Hemangioma / Q000235:genetics / Q000473:pathology; D006801:Humans; D017495:Hyperpigmentation / Q000473:pathology*; D038061:Lower Extremity Deformities, Congenital / Q000473:pathology*; D008297:Male; D020752:Neurocutaneous Syndromes / Q000175:diagnosis* / Q000473:pathology*; D009508:Nevus, Pigmented / Q000235:genetics / Q000473:pathology; D012535:Scalp / Q000473:pathology*; D013684:Telangiectasis / Q000473:pathology*; D038062:Upper Extremity Deformities, Congenital / Q000473:pathology