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Pretibial dystrophic epidermolysis bullosa: a recessively inherited COL7A1 splice site mutation affecting procollagen VII processing
Author(s) -
Betts C.M.,
Posteraro P.,
Costa A.M.,
Varotti C.,
Schubert M.,
BrucknerTuderman L.,
Castiglia D.
Publication year - 1999
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1046/j.1365-2133.1999.03155.x
Subject(s) - epidermolysis bullosa dystrophica , epidermolysis bullosa , mutation , procollagen peptidase , medicine , rna splicing , genetics , dermatology , biology , pathology , gene , rna
Pretibial epidermolysis bullosa (PEB) is a rare form of localized epidermolysis bullosa dystrophica (EBD), a heterogeneous group of inherited, blistering diseases characterized by scarring, loss of dermal–epidermal adhesion and altered anchoring fibrils (AF). Mutations in the type VII collagen gene (COL7A1) underlie EBD and in a dominant PEB family a glycine substitution mutation has been identified. We report a 33‐year‐old man affected by PEB showing abnormal AF and reduced immunostaining for type VII collagen. Mutation search in the COL7A1 gene revealed a 14 bp deletion in the 115 exon–intron boundary (33563del14), which resulted in the in‐frame skipping of exon 115 with elimination of 29 amino acids from the pro‐α1(VII) polypeptide chain. As a consequence, procollagen VII failed to be processed to mature collagen VII and accumulated at the dermal–epidermal junction , as revealed by immunofluorescence staining using a NC‐2 domain‐specific antibody. The proband’s father was a clinically unaffected heterozygous carrier of mutation 33563del14, whereas the maternal pathogenetic mutation has still not been identified. This represents the first report of a recessive deletion mutation in PEB and extends the range of EBD phenotypes associated with mutation 33563del14.