Mutation analysis in the family of a Taiwanese boy with with epidermolysis bullosa simplex dowling-meara.
Epidermolysis bullosa simplex (EBS) is a group of hereditary bullous diseases characterized by intraepidermal blistering due to mechanical stress-induced degeneration of basal keratinocytes. The major subtypes of EBS, including EBS Dowling-Meara (EBS-DM), are caused by mutations of the basal keratin genes, keratin 5 (KRT5) or keratin 14 (KRT14). Here, we describe the first reported pedigree of EBS-DM in Taiwan. The proband was a 5-day-old newborn, who presented with numerous blisters of various sizes, some of which were hemorrhagic, as well as erosions on the extremities and hard palate since birth. Biopsy of a new vesicle showed subepidermal and basal cleavage with infiltration of eosinophils and neutrophils. Electron microscopy revealed cytolysis of basal cells and clumping of tonofilaments forming thick bundles and peculiar electron-dense round or oval basket-weave bodies. These features are characteristic of EBS-DM. The proband's mother had also suffered from a similar blistering disorder since birth, with gradual appearance of mottled pigmentation on the trunk, diffuse irregular or linear palmoplantar hyperkeratosis, and nail dystrophy. Mutation analysis revealed a heterozygous point mutation (R125C) in helix 1A of keratin 14 in the proband and his mother. The detection of this pathogenic point mutation enables future prenatal diagnosis in this family.
Ning
C C
CC
Department of Dermatology, National Cheng-Kung University Hospital, Tainan, Taiwan.
Chao
S C
SC
Uitto
J
J
Shieh
C C
CC
Lee
J Y
JY
D004252:DNA Mutational Analysis; D016110:Epidermolysis Bullosa Simplex / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007231:Infant, Newborn; D007633:Keratins / Q000235:genetics; D008297:Male; D010375:Pedigree; D017354:Point Mutation; D012867:Skin / Q000473:pathology
D007633:Keratins