Insuring a Selkirk Rex: the polycystic kidney disease inherited from its Persian ancestry
The Selkirk Rex owes its curly coat to a spontaneous mutation that appeared in 1987, but its overall constitution owes a great deal to a breeding choice: to fix the type and coat texture, early breeding programmes crossed the line heavily with Persians and Exotic Shorthairs. That genetic inheritance is not without health consequences. The Selkirk Rex breed profile covers the rest of its profile.
A Persian disease, passed on through crossbreeding
Autosomal dominant polycystic kidney disease (PKD) is the best-documented inherited disease in cats. Leslie Lyons, David Biller, Carolyn Erdman and colleagues identified its cause in 2004 in a study published in the Journal of the American Society of Nephrology: a single-nucleotide variant in exon 29 of the PKD1 gene, truncating roughly a quarter of the protein (study on Google Scholar). That same study, covering Persian and Persian-cross populations, put disease prevalence at around 38% in Persians worldwide — close to 6% of all cats tested across every breed. Inheritance is dominant: a single copy of the mutation, from just one parent, is enough to cause disease — which explains how quickly it spreads through any breed that has taken on Persian bloodlines, Selkirk Rex included.
What that means in practice
PKD causes multiple cysts to form progressively in both kidneys, growing larger with age until they compress healthy kidney tissue. The course is slow and silent for years: a cat can look perfectly healthy until chronic kidney failure appears, typically between 3 and 10 years old. No treatment reverses existing cysts; management is limited to slowing the progression of kidney failure once it has set in.
Screening before choosing an insurance policy
Two methods exist: a DNA test, which looks directly for the mutation from a cheek swab, and a kidney ultrasound, which detects visible cysts from around 10 months old in the hands of an experienced operator. The practical difference matters for pet insurance: a kidney condition already diagnosed at the time of application is excluded from cover by every insurer, without exception. Taking out a policy before any screening, from kitten age, is therefore a real advantage if a positive result comes back later. Our benchmarks are in insuring a Selkirk Rex and in the general guide pet insurance for cats, worth it.
What to ask a breeder
A serious cattery provides dated, named results for both parents — a DNA test or a recent ultrasound. A negative result in both parents rules out the risk in the kittens; a single positive parent statistically puts half the litter at risk. The rest of the everyday equipment and accessories worth knowing about is in cat accessories.
Frequently asked questions
Are all Selkirk Rex cats at risk of PKD?
No, only those that inherited the mutation, directly or through a Persian or Exotic Shorthair ancestor. The test tells you for certain.
Can a kitten that tests negative develop the disease later?
No: the DNA test detects the mutation itself, present from birth if it exists at all. A negative result is definitive.
At what age should an ultrasound be done if the DNA test is not available?
From around 10 months, most detectable cysts are already visible; a follow-up scan around age 3 confirms an early negative result.
This guide is part of Planète Pets’s Cats universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.