title: Epidermolysis bullosa simplex associated with pyloric atresia is a novel clinical subtype caused by mutations in the plectin gene (PLEC1).
abstract: Epidermolysis bullosa (EB) is an inherited mechano-bullous disorder of the skin, and is divided into three major categories: EB simplex (EBS), dystrophic EB, and junctional EB (JEB). Mutations in the plectin gene (PLEC1) cause EBS associated with muscular dystrophy, whereas JEB associated with pyloric atresia (PA) results from mutations in the alpha6 and beta4 integrin genes. In this study, we examined three EB patients associated with PA from two distinct families. Electron microscopy detected blister formation within the basal keratinocytes leading to the diagnosis of EBS. Surprisingly, immunohistochemical studies using monoclonal antibodies to a range of basement membrane proteins showed that the expression of plectin was absent or markedly attenuated. Sequence analysis demonstrated four novel PLEC1 mutations. One proband was a compound heterozygote for a nonsense mutation of Q305X and a splice-site mutation of 1344G-->A. An exon-trapping experiment suggested that the splice-site mutation induced aberrant splicing of the gene. The second proband harbored a heterozygous maternal nonsense mutation, Q2538X and homozygous nonsense mutations R1189X. Analysis of the intragenic polymorphisms of PLEC1 suggested that R1189X mutations were due to paternal segmental uniparental isodisomy. These results indicate that PLEC1 is a possible causative gene in this clinical subtype, EBS associated with PA. Furthermore, two patients out of our three cases died in infancy. In terms of clinical prognosis, this novel subtype is the lethal variant in the EBS category.
authors.affiliation: Department of Dermatology, Hokkaido University Graduate School of Medicine, North 15, West 7, Sapporo 060-8638, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sawamura
authors.forename: Maki
authors.initials: M
authors.lastname: Goto
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.forename: James R
authors.initials: JR
authors.lastname: McMillan
authors.forename: Susam
authors.initials: S
authors.lastname: Park
authors.forename: Sumio
authors.initials: S
authors.lastname: Kono
authors.forename: Shiro
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Son'e
authors.initials: S
authors.lastname: Paku
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yoshihumi
authors.initials: Y
authors.lastname: Ogiso
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimizu
mesh_terms: D016110:Epidermolysis Bullosa Simplex / Q000150:complications / Q000175:diagnosis* / Q000235:genetics*; D005260:Female; D005804:Genes, Lethal; D006801:Humans; D007231:Infant, Newborn; D007381:Intermediate Filament Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D008297:Male; D009154:Mutation / Q000235:genetics; D010375:Pedigree; D051190:Plectin; D011708:Pylorus / Q000002:abnormalities*
chemical_list: D007381:Intermediate Filament Proteins; C495332:PLEC protein, human; D051190:Plectin