title: Two cases of recessive dystrophic epidermolysis bullosa diagnosed as severe generalized.
abstract: Recessive dystrophic epidermolysis bullosa (RDEB) is a congenital bullous disease resulting from defective anchoring fibrils at the dermal-epidermal junction and mutations in the type VII collagen gene. In this report, we describe two patients with severe generalized RDEB. Patient 1 was a 24-day-old male infant, and patient 2 was a 1-day-old female infant. Immunofluorescence microscopy demonstrated absence of type VII collagen labeling in a skin sample of patient 1, and reduced staining in patient 2. Electron microscopy revealed absence of anchoring fibrils below the lamina densa in patient 1, and reduced or rudimentary anchoring fibrils in patient 2. Mutation analyses of COL7A1 in these patients revealed heteroallelic recessive mutations which resulted in premature termination codons (PTC): 6573+1G>C in intron81 and 886del6ins14 in exon 7 in patient 1, and 6573+1G>C in intron81 and 4535insC in exon 44 in patient 2. Heteroallelic combinations of PTC mutation generally result in the severe generalized type. Patient 2 has developed a digital fusion at age 2, which is a typical manifestation of severe generalized RDEB. The RDEB subtype is considered to be determined based on comprehensive information, including analysis of alleles, protein expression, ultrastructure and clinical symptoms after growth. However, mutation analyses of COL7A1 can provide valuable information estimating a diagnosis in early infancy.
authors.affiliation: Department of Dermatology, Gifu University Graduate School of Medicine, Gifu City, Gifu.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ohashi
authors.forename: En
authors.initials: E
authors.lastname: Shu
authors.forename: Miki
authors.initials: M
authors.lastname: Nagai
authors.forename: Kana
authors.initials: K
authors.lastname: Murase
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakano
authors.forename: Katuto
authors.initials: K
authors.lastname: Tamai
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sawamura
authors.forename: Takako
authors.initials: T
authors.lastname: Hiroka
authors.forename: Mariko
authors.initials: M
authors.lastname: Seishima
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kitajima
authors.forename: Yumi
authors.initials: Y
authors.lastname: Aoyama
mesh_terms: D001483:Base Sequence; D018389:Codon, Nonsense; D024143:Collagen Type VII / Q000235:genetics* / Q000378:metabolism; D004252:DNA Mutational Analysis; D016108:Epidermolysis Bullosa Dystrophica / Q000145:classification / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence
chemical_list: C569053:COL7A1 protein, human; D018389:Codon, Nonsense; D024143:Collagen Type VII