Hereditary Cataract Terrier Type
Primary hereditary cataract (HC) is one of the most common genetic disorders in purebred dogs, affecting approximately 100 breeds and representing a leading cause of blindness in dogs. Recessive form of HC in Staffordshire Bull Terriers and French Bulldogs, and juvenile hereditary cataract Terrier type in Boston Terriers is caused by a single nucleotide insertion in HSF4 gene, encoding for a heat shock transcription factor that regulates the expression of heat shock proteins in response to different stresses, such as oxidants, heavy metals, elevated temperatures and bacterial and viral infections.
HC in mentioned breeds is bilateral, symmetrical in the two eyes, and progressive until total with resultant blindness. It appears at a few weeks to months in age, progressing to total by 2 to 4 years of age. Affected dogs are homozygous for the mutation.
The occurrence of hereditary cataract Terrier type in the Boston Terrier is 11.11%.
Mellersh, C.S., Pettitt, L., Forman, O.P., Vaudin, M., and Barnett, K.C. (2006). Identification of mutations in HSF4 in dogs of three different breeds with hereditary cataracts. Veterinary Ophthalmology 9, 369–378.
Mellersh, C.S., Graves, K.T., McLaughlin, B., Ennis, R.B., Pettitt, L., Vaudin, M., and Barnett, K.C. (2007). Mutation in HSF4 associated with early but not late-onset hereditary cataract in the Boston Terrier. Journal of Heredity 98, 531–533.