In humans, there are two modes of inheritance: autosomal dominant and autosomal recessive (with at least two, and possibly three different autosomal dominant forms of PKD caused by different genes at different loci). To date, only the autosomal dominant form has been identified in cats. To quote Dr. DiBartola, Professor of Veterinary Clinical Sciences at The Ohio State University College of Veterinary Medicine, and Co-Editor of the Journal of Veterinary Internal Medicine (one of the Dr.

PKD (Polycystic Kidney Disease) is a progressive, genetic disease of the kidneys. It occurs in humans, cats, dogs, and other animals. PKD is characterized by the presence of multiple cysts in each Kidney (i.e, bilateral). (See also Is a Single Cyst in One Kidney Conclusive for PKD? and Can Kidney Cysts be Caused by Something Other Than PKD?, below). Research at Ohio State University conducted by Dr.

Currently, the best method to diagnose PKD in living cats is by ultrasounding the kidneys. Other radiological modalities have been used, but have proven to be generally less accurate and more costly. However, even the most skilled sonographer using the best equipment cannot be 100 percent accurate in diagnosing PKD via ultrasound, since the resolution afforded by ultrasound is not sufficient to detect very small cysts.

PKD itself has no symptoms. Only when PKD has progressed to the point of causing renal failure will symptoms occur, and those symptoms will be those associated with renal failure, and not PKD specific. quot;Many cats with PKD will never develop kidney failure so they will have no physical symptoms at all. Their routine blood tests will be normal. Other cats will develop kidney failure, depending on the severity of their disease and how rapidly the cysts grow.

Genetics may play a role in PMDD. Studies have shown that identical twins are more likely to share the disorder (93%) than non-identical (fraternal) twins (44%), and daughters of mothers with PMDD are more likely to have it themselves. However, no specific genes have been identified to account for PMDD. It is best to simply say that genetics may put a woman at greater risk for developing the disorder.

There is a genetic factor in the development of allergic disease. If one parent has allergic disease, the estimated risk of a child to develop allergies is 48%; the child's estimated risk grows to 70% if both parents have a history of allergies.

Research shows that the risk for developing alcoholism does indeed run in families. The genes a person inherits partially explain this pattern, but lifestyle is also a factor. Currently, researchers are working to discover the actual genes that put people at risk for alcoholism. Your friends, the amount of stress in your life, and how readily available alcohol is also are factors that may increase your risk for alcoholism. But remember: Risk is not destiny.

Research shows that ADHD tends to run in families, so there are likely to be genetic influences. Children who have ADHD usually have at least one close relative who also has ADHD. And at least one–third of all fathers who had ADHD in their youth have children with ADHD. Even more convincing of a possible genetic link is that when one twin of an identical twin pair has the disorder, the other is likely to have it too.

Genetics is a complex subject, and The Foundation Fighting Blindness has prepared another booklet, "The Inheritance of Retinal Degenerations," to explain this topic in detail. (This can be ordered by using The Foundation's Publication Order Form.) There are so many different forms of RP, which fall within one of three standard inheritance patterns. Each type of inheritance will create a different pattern of affected and unaffected family members.

Most cases of PWS are attributed to a spontaneous genetic error that occurs at or near the time of conception for unknown reasons. In a very small percentage of cases (2 percent or less), a genetic mutation that does not affect the parent is passed on to the child, and in these families more than one child may be affected. A PWS-like disorder can also be acquired after birth if the hypothalamic portion of the brain is damaged through injury or surgery.

Most cases of epilepsy are not inherited, although some types have a genetic basis. Most of these types are easily controlled with medication. Epilepsy syndromes with a genetic basis: Primary Generalized Epilepsies, Benign Rolandic Epilepsy, Nocturnal Frontal Lobe Epilepsy, Familial Temporal Lobe Epilepsy, Benign Familial Neonatal Seizures and Benign Familial Infantile Spasms.

Only 3 to 5% of cases are inherited; the rest arise as an accident of chromosome arrangement during meiosis. For details, see my essay on the origin of trisomy 21 or Dr. Paul Benke's essay on the types of DS, and the risk and recurrence risk of DS. No. Down syndrome occurs at conception, so nothing in the pregnancy can cause Down syndrome to occur. As for prior to conception, the research all shows that drug or alcohol use does not increase the risk of having a child with DS.

To date, there is no proof whether PKD positive homozygotes (PP) exist or not. We may not know the answer to this question until a DNA test is available and that test has been used on a significant number of PKD positive cats. quot;In all likelihood, the homozygous state (PP) for ADPKD probably is not viable.

Based on Dr. Biller's research, and reports from more than 5,000 ultrasounds worldwide since April, 1998, PKD does not appear to be sex linked. Therefore, males and females can both have PKD, and can both pass PKD on to their offspring.

No. Although PKD appears to be more prevalent among Persians (including Himalayans) and Exotics, ultrasound results to date have also found PKD in American Curls, American Shorthairs, Siamese and Scottish Folds, as well as Household Pets, Domestic Shorthairs, and Feral cats. An Oriental Shorthair was also diagnosed with PKD as the result of a necropsy.

Although anyone with access to ultrasound equipment and minimal knowledge of ultrasound can do the testing, the quality and accuracy of the test results appear to be directly proportional to the skill, training, and experience of the sonographer doing the testing. Ultrasound testing can be expensive (as high as $275 US per cat in some private practices, and $25 to $50 US per cat in special PKD "Clinics").

Yes. However, cysts in non-Persian cats are relatively rare, regardless of the cause. So the current theory is that almost all cysts found in Persians and related breeds will be PKD cysts. Dr. Biller will be conducting research to help establish exactly how frequently cysts are found in non-persian cats. This study should help us understand the frequency of non-PKD kidney cysts in Persians, and possibly even provide clues about how they can be differentiated from PKD cysts using ultrasound.

No, at least not in Persians. PKD positives have been found in virtually all major lines of Persians. However, it is at least possible that a few lines with very small gene pools, particularly if they are not descended from the hand-full of pre-potent cats upon which many of today's Persians owe their lineage, may not have PKD in those lines. However, it is also important to note that virtually all major lines of Persians have PKD negative cats too.

No. All evidence to date suggests that there is no relationship between a cat's color and the presence or frequency of PKD.

If a normal cat lived forever, PKD cats would eventually progress to the point where renal failure occurs, and would eventually die of renal failure. However, in real life, it is believed that most PKD cats actually die from something other than renal failure due to PKD. So the practical answer to this question is no, most PKD positive cats will not die from PKD. However, as Dr. DiBartola notes in a private e-mail, in the Ohio study he and Dr.

There is currently no known cure for PKD, in cats or in humans. While a Kidney Transplant may eliminate the cysts and allow a particular individual to live symptom free, the underlying genetic makeup for that individual is still one of a PKD positive, and that individual can still pass the disease on to its offspring. Similarly, dialysis can replace the function of failed kidneys, but does not change the underlying disease state.

Based on all available information, not many Persian catteries of any size have zero positives, at least unless they've already tested and eliminated positives from their breeding program. So if "unscathed" means "no PKD positives", the answer is that not many catteries are unscathed. And because we've never been able to identify PKD positives before, the only reason any cattery would be unscathed is pure, blind luck.

Why? Because PKD is a genetic disease, not a communicable disease. So any cattery lucky enough to have only PKD negative foundation stock AND never bring in a PKD positive cannot produce PKD positive cats, and thus will be a PKD free cattery.

PKD expresses itself differently in each cat. And, based on the best information available, it appears that most PKD positive cats die from other reasons -- not from End Stage Renal Failure resulting from PKD. So it is entirely possible to have PKD positives and never have a cat exhibit the signs of renal failure, much less die from PKD. PKD can only be detected by ultrasound or necropsy. Most if not all PKD cases would be picked up on necropsy with histopathology, if that were routinely done.

There's a useful web site which reports statistics on PKD testing to date. Although I'm sure there are many catteries who, for one reason or another, have chosen not to report their results, I find this the best source of information currently available. Taking the stats for US Catteries through 10/8/98 and using MS Excel to manipulate the data, I came up with the following information: Slightly less than one half of the US cats tested are included in the Cattery stats (1547 vs.

That depends upon the extent that you want to understand PKD. At the lowest level -- that PKD is an inherited disease that can be largely eliminated by ultrasounding breeding stock and removing positives from your breeding program -- there's probably no need to understand genetics. However, if you're the type of person who wants to understand as much about PKD as possible, then you will need to understand the genetic terminology that frequents discussions about PKD.