Dry Eye Curly Coat Syndrome

(Congenital keratoconjunctivitis sicca and ichthyosiform dermatosis, CKSID)

 

Gene: FAM83H

Transmission: Autosomal recessive

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Deletion, FAM83H gene; c.1015 del.C, p.(P326H fs STOP 258), exon5

Medical systems: Vision, skin

Breed: Cavalier King Charles Spaniel

Age of onset of symptoms: 2 to 10 weeks

Dry Eye, Curly Coat Syndrome is a genetic disease seen in the Cavalier King Charles Spaniel breed of dog.  Symptoms are present at birth but are more evident after 2 weeks.  The affected animal has reduced production of tears from the lacrimal gland, resulting in dry eyes, irritation of the cornea, increased risk of corneal ulcers, and often a mucoid greenish ocular discharge.  If untreated, these symptoms can lead to blindness.  The affected animal also suffers from dry skin (ichthyosis) and has a coat that is abnormally rough and curly.  Thickening (hyperkeratinisation) of the foot pads, slowed growth and dental disorders ccan also be associated with the disease.  Due to the difficulty of adequately treating this disease, affected animals are often euthanized.

 

References:

OMIA link: [1683-9615]

Genetics Committee of the American College of Veterinary Opthalmologists (2021) The Blue Book: Ocular disorders presumed to be inherited in purebred dogs. 13th Edition.  [https://ofa.org/wp-content/uploads/2022/10/ACVO-Blue-Book-2021.pdf]

Nimmo JS, McMillan E, Sofronidis G. (2020) Congenital keratoconjunctivitis sicca and ichthyosiform dermatosis in a Cavalier King Charles spaniel with a single defective copy of the FAM83H gene. Aust Vet Pract 50:41-46.  [Aust Vet Pract link]

Forman OP, Penderis J, Hartley C, Layward LJ, et al. (2012) Parallel mapping and simultaneous sequencing reveales deletions in BCAN and FAM83H associated with discrete inherited disorders in a domestic dog breed.  POoS Genetics 8(1):e1002462. [pubmed/22253609]

Hartley C, Barnett KC, Pettitt L, Forman OP, Blott S, Mellersh CS. (2012) Congenital Keratoconjunctivitis Sicca and Ichthyosiform Dermatosis in Cavalier King Charles Spaniel Dogs. Part II: Candidate Gene Study.  Vet Ophthalmol. 2012 Sep;15(5):327-32.  [pubmed/22339941]

Hartley C, Donaldson D, Smith KC, et al. (2012) Congenital keratoconjunctivitis sicca and ichthyosiform dermatosis in 25 Cavalier King Charles spaniel dogs – Part I: clinical signs, histopathology, and inheritance. Vet Ophthalmol. 15(5):315-26. [pubmed/22212237]

Barnett KC. (2006) Congenital keratoconjunctivitis sicca and ichthyosiform dermatosis in the cavalier King Charles spaniel. J Small Anim Pract. 47(9):524-8. [pubmed/16961470]