Mucopolysaccharidosis (Storage Disease, Metabolic Disorders Due to Enzyme Deficiency) in cats
- Occurrence: very rare
- Location of illness: General/Whole body
Mucopolysaccharidosis (MPS) in cats is a genetically determined metabolic disease caused by a deficiency of specific enzymes. These enzymes are necessary for the breakdown of mucopolysaccharides, also known as glycosaminoglycans, which accumulate in the body cells and lead to various health problems.
The most important facts at a glance
Mucopolysaccharidosis (MPS) is a lysosomal storage disease in cats caused by an enzyme deficiency. This deficiency prevents the breakdown of glycosaminoglycans (GAGs), leading to the accumulation of these substances in the cells and causing cell and organ damage. The disease is inherited through an autosomal recessive genetic mutation that must come from both parents for a cat to develop symptoms. Typical symptoms include Stunted growth, bone diseases and skeletal deformities, limited joint mobility, Congestive heart failure, and shortness of breath. Diagnosis is made through clinical signs, X-rays, and specific laboratory tests that measure enzyme activity and can detect elevated GAG concentrations in the urine. Genetic tests help identify the specific mutation and are important for breeders to identify carriers of the mutation. Treatment focuses on alleviating symptoms through physiotherapy, pain medication, and in some cases, enzyme replacement therapies or surgical procedures. The prognosis varies depending on the severity of the disease; while some cats can lead a relatively normal life, life expectancy is often shortened in severe forms. For prevention, it is important to carry out targeted breeding programs and use genetic tests to prevent the spread of the disease. Another preventive approach is to educate breeders and cat owners about the disease and the importance of regular veterinary examinations.
Causes
Mucopolysaccharidosis belongs to a group of diseases known as lysosomal storage diseases. These diseases arise from the defect or deficiency of a specific lysosomal enzyme that is normally responsible for breaking down certain substances. In MPS, it involves the breakdown of glycosaminoglycans (GAGs), which consist of long chains of sugar molecules.
These GAGs are important components of connective tissues, cartilage, and other structures in the body. Normally, they are continuously broken down and renewed. In cats with MPS, the enzyme deficiency means that these substances cannot be broken down properly and accumulate in the cells. This accumulation leads to progressive damage to the cells, tissues, and organs.
The cause of MPS is a mutation in one of the genes responsible for producing the required enzymes. This genetic mutation is inherited in an autosomal recessive manner, meaning that a cat must inherit the mutation from both parents to develop symptoms of the disease.
Symptoms
The symptoms of MPS in cats are diverse and vary depending on the severity and the specific type of the disease. The most common signs include skeletal deformities such as shortened limbs or deformities of the spine, which can lead to Limited mobility. Cats may also suffer from growth delays.
Other symptoms include cloudy eyes or corneal opacities, which can lead to Visual disturbances. Some cats show neurological symptoms such as ataxia (Coordination disorders) or Convulsions. Respiratory problems, caused by narrowed airways, are also possible.
In severe cases, heart problems can occur, including heart valve diseases. The accumulation of GAGs in the internal organs can also cause liver and spleen enlargement, leading to further health complications.
Diagnosis
The diagnosis of MPS in cats is based on a combination of clinical signs, X-rays, and specific laboratory tests. A thorough physical examination can provide clues to skeletal and eye changes. X-rays can reveal skeletal abnormalities typical of MPS.
To confirm the diagnosis, specific laboratory tests are necessary to measure the activity of the affected enzymes. These tests can be performed on blood samples or skin biopsies. In addition, urine samples can be examined for the presence of elevated GAG concentrations.
Genetic tests are also available and can help identify the specific mutation that causes MPS. These tests are particularly useful for breeders to identify carriers of the mutation and prevent the spread of the disease.
Therapy
The treatment of MPS in cats focuses on alleviating the symptoms and improving the quality of life, as there is currently no cure for the disease. Physiotherapy and pain medication can help improve limited mobility and relieve Pain.
In some cases, enzyme replacement therapies may be considered to compensate for the deficiency of certain enzymes. However, these therapies are still in the development phase and not widely used.
In addition, surgical intervention may be necessary to correct specific problems, such as the removal of cloudy corneal tissue or the correction of severe skeletal deformities. Regular veterinary examinations are crucial to monitor the progression of the disease and adjust the treatment accordingly.
Prognosis and follow-up care
The prognosis for cats with MPS varies considerably depending on the type of disease and the severity of the symptoms. While some cats with mild forms of the disease can lead a relatively normal life, life expectancy is often greatly reduced in more severe forms.
Affected cats usually require lifelong treatment and monitoring to maintain their quality of life. Early diagnosis and timely treatment can help alleviate symptoms and prolong life. Nevertheless, MPS remains a progressive disease that ultimately leads to a deterioration in health.
Prevention
Targeted breeding programs are crucial for the prevention of mucopolysaccharidosis in cats. Since it is a genetic disease, avoiding the mating of affected or identified carrier cats is an effective measure. Genetic tests can help identify carriers of the disease, even if they show no symptoms.
Another preventive approach is to educate breeders and cat owners about the importance of genetic testing and the potential risks of the disease. By raising awareness of this metabolic disorder, informed decisions can be made in breeding. In addition, education about the disease can help ensure that affected cats are recognized early and supported in the best possible way.
Regular veterinary examinations also play an important role in monitoring the cat’s general health and identifying potential problems early. Although there is no cure, these measures can help reduce the spread of the disease within cat populations and improve the quality of life of affected animals.