Compound heterozygosity in sibling patients with recessive dystrophic epidermolysis bullosa associated with a mild phenotype.
We describe two cases of a 3-year-old Japanese boy and his 1-year-old sister presenting recessive dystrophic epidermolysis bullosa; a relatively mild phenotype. Blistering and scarring were limited to the acral region, and some fingernails and toenails were lost. PCR-RFLP and DNA sequencing analyses revealed compound heterozygotes for a splice-site mutation (6573 +1GtoC) and a nonsense mutation (E2857X) in the type VII collagen gene (COL7A1). Both mutations caused a premature termination codon (PTC). The mutation E2857X was located behind the candidate cleavage site within the NC-2 domain required for the assembly of anchoring fibrils. This PTC position may explain their mild phenotype.
From the Department of Dermatology, Gunma University Graduate School of Medicine, Maebashi, Japan. yshibusa@showa.gunma-u.ac.jp
Y
Y
Shibusawa
I
I
Negishi
O
O
Ishikawa
D002675:Child, Preschool; D024143:Collagen Type VII / Q000235:genetics*; D016108:Epidermolysis Bullosa Dystrophica / Q000235:genetics*; D005260:Female; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007564:Japan; D008297:Male; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D035781:Siblings
D024143:Collagen Type VII