Pyruvate Kinase Deficiency in Cats: A Comprehensive Guide

Introduction

Pyruvate kinase deficiency (PK Def.) is a genetic disease that occurs particularly in certain breeds of cats. This disease, caused by a mutation in the PKGL gene, leads to a shortened lifespan of red blood cells and results in anemia. In this article, we take a thorough look at PK deficiency, from its genetics to recommended tests.

What is Pyruvate Kinase Deficiency in Cats?

Pyruvate kinase deficiency in cats is an inherited disorder that affects the liver and blood. Pyruvate kinase is a crucial enzyme in the glycolytic process, and its dysfunction leads to the destruction of red blood cells, resulting in anemia. Affected cats show symptoms such as lethargy, weakness, weight loss, jaundice and an enlarged abdominal cavity.

Genetic basis of pyruvate kinase deficiency in cats

PK deficiency is caused by a mutation in the PKGL gene, specifically the mutation c.693+304G>A. This mutation is located 53 nucleotides from the splice site in exon 6 and results in a 13 bp deletion at the 3' end of exon 5. This genetic change affects the production of the pyruvate kinase enzyme in the liver and blood.

Prevalence and affected breeds for pyruvate kinase deficiency in cats

The frequency of pyruvate kinase deficiency (PK Def.) varies significantly between different cat breeds. This genetic disease mainly affects breeds in which a specific mutation in the PKGL gene has been identified. Here is a detailed overview of the frequency of PK deficiency in some of the most commonly affected breeds:

1. Abyssinian and Somali cats: These breeds are particularly susceptible to PK deficiency. Studies show a relatively high prevalence of the condition, meaning breeders and owners should be particularly vigilant.
2. Bengal cats: A higher frequency of PK deficiency has been found in Bengal cats. This highlights the importance of genetic testing before breeding to prevent the spread of the disease.
3. European Shorthair Cats: PK deficiency has also been detected in this breed, although not as frequently as in the breeds mentioned above.
4. Egyptian Mau cats, LaPerm cats, Maine Coon cats, Norwegian Forest cats, Savannah cats, Siberian cats, Singapore cats: These breeds also have an increased risk of PK deficiency. Breeders and cat owners should be aware of the possible genetic predisposition and have appropriate preventive examinations carried out.
5. Exotic shorthair cats, Oriental shorthair cats and Persian cats: A lower frequency of the mutation was found in these breeds. However, it is important that breeders and owners are aware of this possibility, especially when crossed with other breeds.

It is crucial to understand that these frequencies are based on studies and may change over time, especially as breeders actively work to prevent the spread of this condition. Regular genetic testing and responsible breeding practices are essential to minimize the spread of PK deficiency in affected breeds. Cat owners should always consult with their veterinarian to ensure the best course of action for their cat's health and well-being.

Source : https://savannahcatassociation.org/pk-deficiency/

Symptoms of pyruvate kinase deficiency in cats

Pyruvate kinase deficiency (PK Def.) in cats is an inherited disease that can cause various symptoms depending on the severity of the disease. The main cause of symptoms is a shortened lifespan of red blood cells, leading to anemia. Here are some of the most common symptoms that can be seen in cats with PK deficiency:

1. Lethargy: Affected cats often show reduced activity and appear tired or lethargic. This is due to the reduced oxygen supply to the body caused by anemia.
2. Weakness: Cats may be weak due to anemia. This can manifest itself in reduced physical strength and general weakness.
3. Weight loss: Another common symptom is unexplained weight loss, which can also be exacerbated by loss of appetite.
4. Jaundice (jaundice): The breakdown of red blood cells can cause yellowing of the skin, mucous membranes and the white parts of the eyes.
5. Enlargement of the abdominal cavity: In some cases, an enlargement of the abdomen may be observed, which may indicate an accumulation of fluid or an enlargement of the internal organs.
6. Difficulty breathing: Due to anemia, there may be an increased need for breathing as the body tries to compensate for the lack of oxygen.

It is important to note that these symptoms can also occur with other medical conditions. Therefore, an accurate diagnosis by a veterinarian, including specific genetic testing, is essential to ensure correct treatment. If PK deficiency is suspected, veterinary help should be sought immediately to ensure the well-being and quality of life of the affected cat.

Diagnosis of pyruvate kinase deficiency in cats

Diagnosis of pyruvate kinase deficiency (PK Def.) in cats is a multi-step process aimed at identifying this specific genetic disorder and distinguishing it from other similar health problems. Here I explain in detail the different steps and methods used in diagnosing PK deficiency:

1. History and Clinical Symptoms: The first step is to assess the cat's medical history and the symptoms observed. Typical signs such as lethargy, weakness, weight loss, jaundice and abdominal swelling can indicate PK deficiency, especially if the cat belongs to a high-risk breed.
2. Blood tests: A series of blood tests may be performed to determine anemia and its causes. This includes a complete blood count (CBC) to assess red blood cells and a biochemical profile to check liver function and other important organs.
3. Genetic testing: The definitive diagnosis of PK deficiency is made through genetic testing. DNA is taken from a blood sample or a cheek swab from the cat and examined for the specific mutation in the PKGL gene. This test is crucial because it not only identifies sick animals, but also carriers of the mutation that may appear healthy on the outside.
4. Further diagnostic testing: In some cases, additional testing may be necessary to rule out other possible causes of symptoms or to better understand the extent of the disease. This may include ultrasound scans, x-rays and special blood tests.
5. Advice and aftercare: After the diagnosis has been made, comprehensive advice from the veterinarian is important. This includes information about management of the disease, breeding recommendations (particularly for carriers of the mutation), and possible treatment options.

Early and accurate diagnosis of PK deficiency is crucial to providing affected cats with the best possible care and quality of life. Cat owners and breeders should work closely with their veterinarian to monitor the health of their animals and take appropriate action if necessary.

Differential diagnosis of pyruvate kinase deficiency in cats

The differential diagnosis of pyruvate kinase deficiency (PK Def.) in cats involves distinguishing this specific genetic disorder from other conditions that may present with similar symptoms. Careful differentiation is crucial to making a correct diagnosis and ensuring the best possible treatment. Here I explain some important aspects and diseases that should be taken into account as part of the differential diagnosis:

1. Other forms of anemia: Because PK deficiency leads to anemia, it should be differentiated from other forms of anemia. These include hemolytic anemia caused by infections (e.g. feline leukemia virus), toxic influences, immune-mediated diseases or other genetic defects.
2. Liver diseases: Since pyruvate kinase plays an important role in the liver, a differential diagnosis should also consider possible liver diseases, such as hepatitis, cirrhosis or cholangitis.
3. Infectious diseases: Infections such as Feline Infectious Anemia (caused by mycoplasma) can cause symptoms similar to PK deficiency and should be ruled out.
4. Iron deficiency: Iron deficiency, which can also lead to anemia, should be considered as a possible cause, especially if the cat's diet is not balanced.
5. Kidney disease: Chronic kidney disease can also cause anemia. Examination of kidney function can help distinguish PK deficiency from kidney disease.
6. Bone marrow diseases: Bone marrow diseases that affect the production of blood cells should also be considered.

Differential diagnosis requires a combination of thorough history, clinical examinations, blood tests and specific genetic tests. This is the only way to ensure that the correct diagnosis is made and the appropriate treatment is initiated. It is important that cat owners work closely with their veterinarian and provide all relevant information about their cat's health and behavior.

Inheritance pattern of pyruvate kinase deficiency in cats

PK Def is inherited in an autosomal recessive manner. This means that the disease only occurs in cats that inherit the mutated allele from both parents. Carriers of the mutated allele are clinically healthy but can pass the disease on to their offspring. When two heterozygotes are mated, the probability of healthy offspring is 25%, 50% for carriers and 25% for affected cats.

Is there a cure or treatment for pyruvate kinase deficiency in cats?

There is currently no cure for pyruvate kinase deficiency (PK Def.) in cats. Because it is a genetic disease, the focus of treatment is on relieving symptoms and improving the quality of life of affected animals. Here I explain in detail the different approaches and options available for treating and caring for cats with PK deficiency:

1. Supportive care: The basis of treatment is to relieve symptoms and stabilize the cat's general condition. This may include a balanced diet, adjustment of activities and continuous monitoring of health status.
2. Nutritional management: A high-quality diet tailored to the cat's needs can help improve its general condition. Nutrient-rich diets that are easy to digest and provide a good supply of vitamins and minerals are recommended.
3. Blood transfusions: In severe cases of anemia, blood transfusions may be necessary to increase red blood cells and relieve acute symptoms.
4. Drug treatment: Depending on the specific symptoms and comorbidities, various medications may be used. These include, for example, medications to strengthen the immune system, support liver function or treat secondary infections.
5. Regular veterinary checks: Regular veterinary monitoring is crucial to monitor the progression of the disease and adjust treatment if necessary.
6. Awareness and education: It is important for cat owners and breeders to learn about the disease and its effects. This helps to recognize the signs early and take appropriate measures.

Although there is currently no cure for PK deficiency, these measures can help to significantly improve the quality of life of affected cats. It is important that cat owners work closely with their veterinarian to ensure the best care and support for their cat.

Summary Pyruvate kinase deficiency in cats

Pyruvate kinase deficiency in cats is a genetic disease that occurs particularly in certain breeds of cats. Pyruvate kinase deficiency in cats results in a shortened lifespan of red blood cells, leading to anemia. Early diagnosis of pyruvate kinase deficiency in cats is crucial to appropriately treat affected animals. Symptoms of pyruvate kinase deficiency in cats can include lethargy, weakness, and weight loss.

When diagnosing pyruvate kinase deficiency in cats, genetic testing is used to detect the specific mutation in the PKGL gene. The inheritance of pyruvate kinase deficiency in cats is autosomal recessive, meaning that the disease only occurs when two mutated alleles are inherited. Carriers of pyruvate kinase deficiency in cats are often clinically healthy, but can pass on the mutation.

There is no cure for pyruvate kinase deficiency in cats, but supportive treatments can improve quality of life. Pyruvate kinase deficiency in cats often requires dietary and care adjustments. Pyruvate kinase deficiency in cats may require blood transfusions in severe cases.

The prevalence of pyruvate kinase deficiency in cats varies by breed, with higher rates in certain breeds such as Abyssinian and Somali cats. Education about pyruvate kinase deficiency in cats is important to inform breeders and cat owners. Pyruvate kinase deficiency in cats is an example of how genetic screening can be used in animal breeding.

Regular veterinary checks are crucial for cats with pyruvate kinase deficiency. Research into pyruvate kinase deficiency in cats continues to search for better treatment options. Pyruvate kinase deficiency in cats highlights the importance of responsible breeding practices. Cat owners should be aware that pyruvate kinase deficiency in cats is a serious condition that requires special attention.