A de novo variant in the keratin 1 gene (KRT1) in a Chinese shar-pei dog with severe congenital cornification disorder and non-epidermolytic ichthyosis

PLoS One. 2022 Oct 17;17(10):e0275367. doi: 10.1371/journal.pone.0275367. eCollection 2022.

Abstract

A 3-months old Chinese shar-pei puppy with ichthyosis was investigated. The dog showed generalized scaling, alopecia and footpad lesions. Histopathological examinations demonstrated a non-epidermolytic hyperkeratosis. The parents of the affected puppy did not show any skin lesions. A trio whole genome sequencing analysis identified a heterozygous de novo 3 bp deletion in the KRT1 gene in the affected dog. This variant, NM_001003392.1:c.567_569del, is predicted to delete a single asparagine from the conserved coil 1A motif within the rod domain of KRT1, NP_001003392.1:p.(Asn190del). Immunohistochemistry demonstrated normal levels of KRT1 expression in the epidermis and follicular epithelia. This might indicate that the variant possibly interferes with keratin dimerization or another function of KRT1. Missense variants affecting the homologous asparagine residue of the human KRT1 cause epidermolytic hyperkeratosis. Histologically, the investigated Chinese shar-pei showed a non-epidermolytic ichthyosis. The finding of a de novo variant in an excellent functional candidate gene strongly suggests that KRT1:p.Asn190del caused the ichthyosis phenotype in the affected Chinese shar-pei. To the best of our knowledge, this is the first description of a KRT1-related non-epidermolytic ichthyosis in domestic animals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asparagine / genetics
  • China
  • Dogs
  • Humans
  • Hyperkeratosis, Epidermolytic* / genetics
  • Hyperkeratosis, Epidermolytic* / pathology
  • Hyperkeratosis, Epidermolytic* / veterinary
  • Ichthyosis* / genetics
  • Ichthyosis* / veterinary
  • Infant
  • Keratin-1* / genetics
  • Keratin-10 / genetics
  • Keratins / genetics
  • Mutation

Substances

  • Asparagine
  • Keratin-1
  • Keratin-10
  • Keratins
  • KRT1 protein, human

Grants and funding

This research was funded by the Swiss National Science Foundation, grant number 310030_200354 PI: Dr. Tosso Leeb, University Bern Switzerland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.