Chapter 62 Inherited EB Flashcards
keratin ___ and ___ assembles to form filament network of basal cell cytoskeleton
keratin 5 and 14
____ localizes to region referred to as inner plate on cytoplasmic surface of hemidesmosome and like plectin, functions in connection between hemidesmosomes and intermediate filaments
BP230
if negative –> mechanical fragility
collagen XVII also termed ___
BPAG2 / BP180
specific receptor for laminin 332
a6B4 - central role in organization of hemidesmosome
collagen XVII associates w/ laminin 332 and a6B4 integrin in adhesion structures termed
stable anchoring contacts
autoantigen in linear IgA bullous dermatosis
LAD-1
collagen XVII undergoes processing in keratinocyte cultures and in skin through action of
sheddases - membrane associated proteases that solubilizes cell surface receptors
major constituent of anchoring fibrils
collagen VII
collagen VII binds to the ___ chain on laminin 332
B3 chain
gold standard for diagnostic grouping of EB
electron microscopy
most severe of EBS subtypes, Dowling-Meara EBS - onset, manifestation?
at birth generalized oral mucosa more often involved (differ from Koebner) millium formation grouped or hepetiform blisters without scarring trunk, proximal extremities dystrophy of long nails hyperkeratosis of palms and soles (early childhood) flexural contractures esophageal involvement to pyloric atresia natal teeth
Generalized / Koebner EBS
at birth or early infancy
generalized
hands, feet, extremities - most involvement
post inflammatory hypo or hyperpigmentation
atrophy and milia - less frequent
palmoplantar hyperkeratosis, erosions
thickening of soles - later childhood
oral mucosa - mild erosive, improve with age
mildest, most common form of EBS, Localized EBS ?
infancy and childhood mild enough to escape reporting hyperhidrosis of palms, soles post inflamm pigmentary alteration follows trauma; hands and feet common; scalp least milia scarring absent nail rare
EBS of Ogna ?
infancy summer acral without scarring Norway onychogryphosis of great toenails
EBS with muscular dystrophy
at birth or shortly thereafter generalized progressive muscular dystrophy generalized HD1/plectin mutation
EBS w/ mottled pigmentation
at birth or early infancy
trunk, proximal extremities
reticular, increase w/ age
progressive pigmentation
EBS superficialis
subcorneal erosions, crusts post inflammatory pigmentary changes nail atrophic scarring milia
lethal acantholytic EBS
rare recessive at birth generalized dystrophic to absent nails complete alopecia neonatal teeth oral erosions respiratory involvement
ectodermal dysplasia skin fragility syndrome
suprabasilar at birth generalized alopecia palmoplantar keratoderma painful fissures nail dystrophy
which mutation coding for the most highly conserved regions of keratin ___ and ____ correlate w/ dowling meara
K5 and 14
milder forms, weber-cockayne codes for regions that are less conserved
mutations in EBS w/ mottled pigmentation
amino terminus of K5 (globular head domain responsible for keratin filament insertion to melanosomes)
mutations w/ EBS w/ muscular dystrophy
lack of expression or defective expression of plectin
disorganization of muscle sarcomeres
unique case of recessive dominant EBS associated w/ null mutations of_____ gene coding for BP230/BPAG1
dystonin
blistering w/ neuropathy
molecular defect of ectodermal dysplasia skin fragility syndrome - loss of function of desmosomal protein ______, encoded by PKP1
plakophilin 1
suprabasilar keratinocytes and outer root sheath cells
