Test Detail

DNA panel specific to the Persian that combines genetic blood group determination with screening for three hereditary diseases of the breed: alpha-mannosidosis (AMD), polycystic kidney disease (PKD) and AIPL1-associated progressive retinal atrophy (PRA-AIPL1, also called feline Leber congenital amaurosis; in older catalogues it appears as pd-PRA). It covers the metabolic, renal and ocular systems respectively. It is performed from a buccal swab or blood and identifies carrier, affected and predisposed animals. It is essential in a breed with a long history of hereditary diseases.

PKD affected about 40 % of Persians before genetic screening; today the prevalence has decreased notably in controlled populations, and the variant also appears in related breeds. Alpha-mannosidosis is rare today. The allele frequency of the AIPL1 variant in Persian and related breeds is 1.15 % (Lyons et al., 2016; more than 1,700 cats from 40 breeds/populations); it should not be extrapolated to other breeds or to other PRAs.

- PKD: multiple renal cysts with progression to chronic kidney failure (polyuria, polydipsia, weight loss, vomiting)\n- AMD: progressive ataxia, intention tremor, skeletal deformities and recurrent infections in kittens\n- PRA-AIPL1: progressive vision loss with night blindness, mydriasis and tapetal hyperreflectivity\n- Neonatal isoerythrolysis due to blood group incompatibility

Polycystic kidney disease was recognised in the Persian in the last decades of the 20th century, and ultrasound studies in the 1990s revealed prevalences close to 40 % in some series, making it the most common hereditary disease of the breed. In the mid-2000s the causative variant of the PKD1 gene was identified, which enabled a DNA test and a notable reduction in the disease. Alpha-mannosidosis is a classic lysosomal storage disease in the breed, associated with the MAN2B1 gene. Persian PRA is caused by a truncating variant of the AIPL1 gene (c.577C>T, p.Arg193*), described by whole-genome sequencing in cats (Lyons et al., 2016); NOT by CNGA1. The AB blood group system was deciphered in 2007 with the CMAH gene.

- Do not breed animals positive for PKD1: a single carrier parent is enough to transmit the variant; remove them in a planned manner\n- Never cross two carriers of AMD or PRA-AIPL1: expectably 25 % of the litter would be affected\n- Carriers of recessive diseases may be crossed with clear animals without excluding them from the programme\n- Determine the blood group before mating to prevent neonatal isoerythrolysis\n- PRA-AIPL1 should only be interpreted in Persian and related breeds; complement with ophthalmological examinations, since most feline PRAs are not explained by this variant

In PKD, abdominal ultrasound remains useful: the genetic test only detects the known PKD1 variant and other cystic nephropathies exist. When AMD is suspected, measurement of alpha-mannosidase activity in leukocytes and vacuoles in lymphocytes support the diagnosis. PRA-AIPL1 is confirmed with fundus examination and electroretinogram; it must be differentiated from other forms of feline PRA (rdAc of the Abyssinian, rdy), from taurine-deficiency retinopathy and from retinal degeneration secondary to hypertension or uveitis. The Persian PRA gene is AIPL1, not CNGA1.

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11. PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts. 2023. PMID: 39108347
OMIA:000119-9685 (grupo sanguíneo AB); OMIA:000625-9685 (alfa-manosidosis); OMIA:000807-9685 (enfermedad renal poliquística); OMIA:001222-9685 (amaurosis congénita de Leber / PRA-AIPL1).