Categories: Integument (skin) phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 131760 (trait) , 131900 (trait) , 131800 (trait) , 601001 (trait) , 148066 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Disease-related: yes

Key variant known: yes

Year key variant first reported: 2020

History: Dettwiler et al. (2020): "To our knowledge, this is the first report of a spontaneously arising loss of function allele in the KRT14 gene in a domestic animal with EBS, and the first report of feline EBS."

Molecular basis: Dettwiler et al. (2020) reported "a homozygous nonsense variant in the KRT14 gene (c.979C>T, p.Gln327*)" as the likely causal variant in an affected male domestic shorthair cat.

Clinical features: Dettwiler et al. (2020): "At presentation, the cat was lethargic and inappetent. Partial to complete sloughing of the paw pad skin affecting multiple pads with multifocal re‐epithelization underneath was present . . . . The gums, hard palate, buccal mucosa and ventral aspect of the tongue were multifocally ulcerated . . . . Lesions were not contiguous with teeth, which appeared normal. Ulcers were also present at the inner aspect of both pinnae . . . . The cat tested negative for FIV, FeLV, toxoplasma and Coronavirus."

Pathology: Dettwiler et al. (2020): "Biopsy specimens from paw pads and tongue were submitted for histopathological examination. Both tissues displayed a multifocal detachment of the epithelium, without associated interface inflammation . . . . These blisters were roofed by the epithelial basal layer showing an uneven contour . . . . The basement membrane covering the dermis and lamina propria, respectively, was the blister floor, as confirmed by PAS reaction . . . . In areas with adherent epithelium, multifocal cytoplasmic vacuolation of basal keratinocytes was seen . . . . The paw pad tissue was covered with one to two layers of necrotic detached epidermis alternating with serocellular crusts . . . . Paw pad dermis and mucosal connective tissue displayed a mild to moderate mixed inflammation."

Prevalence: Dettwiler et al. (2020): "Sanger sequencing confirmed the mutant allele to be present in a homozygous state in the affected cat and absent from 154 unaffected cats from different breeds."

Associated gene: