Leber Congenital Amaurosis (pd-PRA)

Leber congenital amaurosis, also known as retinal dystrophy of pigment epithelium, is an inherited disease causing severe visual impairment at an early age. In addition to loss of vision, clinical symptoms include abnormal eye movements (nystagmus), impaired pupillary response to light and behavioural changes.

The disease is caused by the nonsense mutation c.577C>T in the AIPL1 gene, which is found in the Persian cat and related breeds. The genetic test is suitable for Persian cats, British Shorthair and Longhair cats, Himalayan cats, Exotic Shorthair and Longhair cats, Napoleon cats and other breeds derived from Persian cats or crossbreeds.

The mode of inheritance of the mutation is autosomal recessive. This means that only individuals who inherit the mutated gene from both parents will develop the disease. Carriers of the mutated gene are clinically healthy but pass the mutation on to their offspring. In the case of a mating between two heterozygous individuals, theoretically 25% of the offspring will be completely healthy, 50% of the offspring will be carriers and 25% of the offspring will inherit the mutated gene from both parents and will therefore be affected by the disease.

The genetic test can clearly reveal the genotype of the animal and is a useful tool for breeders to prevent unintentional breeding of affected kittens.

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References:

Lyons, L.A., Creighton, E.K., Alhaddad, H., Beale, H.C., Grahn, R.A., Rah, H., Maggs, D.J., Helps, C.R., Gandolfi, B. : Whole genome sequencing in cats, identifies new models for blindness in AIPL1 and somite segmentation in HES7. BMC Genomics 17:265, 2016. Pubmed reference: 27030474.