Saturday, March 10, 2012

Congenital Keratoconjunctivitis Sicca and Ichthyosiform Dermatosis in Cavalier King Charles Spaniel Dogs


Hartley C, Donaldson D, Smith KC et al. Keratoconjunctivitis sicca and ichthyosiform dermatosis in 25 cavalier King Charles spaniel dogs - part I: clinical signs, histopathology and inheritance. Veterinary Opthalmology 2011; Epub ahead of print. Abstract. 
PubMed ID (PMID): 22212237
ReprintC. Hartley 
Comments: This syndromic ichthyosis, which does not yet appear to have a human equivalent, was first reported in CKCS in 1994 by Z. Alhaidari (abstract). Clinical signs were further described in 2006, with the publication of a series of 19 cases (abstract). The paper referenced above expands the clinical characterization of the keratoconjunctivitis sicca, the associated keratitis, the possible xerostomia, an abnormal coat and ichthyotic signs (scaling, footpad hyperkeratosis, nail defects) in this breed. Furthermore, it provides some information on microscopic lesions and on the characterization of an autosomal recessive mode of inheritance. In papers recently published, the authors rule-out several candidate genes, which predispose humans to develop Sjögren syndrome or ichthyoses (abstract). They eventually link the canine syndrome with a mutation in exon 5 of FAM83H (family with sequence similarity 83, member H, abstract), a gene whose mutations cause autosomal dominant hypocalcification amelogenesis imperfecta (ADHAI), a disease associated with defective enamel formation. Further characterization of the causal relationship existing between having two copies of the culprit mutation in FAM83H (in the autosomal recessive canine disease), the dry syndrome and the skin hyperkeratosis is eagerly awaited.
Recommended by: Thierry Olivry, NC State University, Raleigh, NC, USA