Skin Barrier, Phenotypic and Genotypic Characterization of Autosomal Recessive Ichthyosis in TGM1-Deficient Jack Russell Terriers and Response to Topical Ceramide

This study examined autosomal recessive ichthyosis in Jack Russell Terriers with TGM1 gene deficiency, where 4 out of 5 puppies were affected, showing severe skin scaling and increased transepidermal water loss (TEWL). The study confirmed that the ichthyosis phenotype is associated with the TGM1 genotype, as affected dogs were homozygous for a LINE-1 insertion in TGM1. Topical ceramide treatment reduced TEWL, indicating potential benefits for skin barrier dysfunction in TGM1-deficient dogs, though the small sample size necessitates further research. Additionally, acylceramides improved skin hydration and pH but did not consistently reduce TEWL, suggesting prolonged treatment might be beneficial despite challenges posed by the dogs' dense haircoat.