What is Chediak-Higashi syndrome?
Chediak-Higashi syndrome is a rare genetic disease of blue smoke Persian cats. This condition affects how the body’s cells process waste products, leading to changes within the cells and abnormal pigmentation of the skin and coat. Chediak-Higashi syndrome is caused by a recessive gene, which means that both parents of an affected cat must be carrying the genetic mutation associated with the syndrome.
What are the clinical signs of Chediak-Higashi syndrome?
Cats with Chediak-Higashi syndrome often have multiple eye abnormalities. They may develop cataracts at an early age, often before three months. When a light is shined into the eye, the reflection often appears red or orange due to abnormal pigmentation of the eye structures. Additionally, some affected cats demonstrate an extreme sensitivity or aversion to light, known as photophobia.
Chediak-Higashi syndrome also affects cells in the immune system. In most cats, these effects are mild, and they do not experience any more illness than unaffected cats. Severely affected cats, however, may experience more frequent infections due to a weakened immune system.
"The most significant effect of Chediak-Higashi syndrome is increased bleeding."
The most significant effect of Chediak-Higashi syndrome is increased bleeding. This is caused by abnormally functioning platelets. Platelets are small cells that are partly responsible for blood clotting. In cats with Chediak-Higashi syndrome, these platelets do not clump together in the way that they should. Therefore, cats with Chediak-Higashi syndrome may bleed excessively after blood draws, surgery, or trauma. Their gums may bleed with irritation and they may have nosebleeds after sneezing.
How is Chediak-Higashi syndrome diagnosed?
Your veterinarian will begin by taking a complete medical history and performing a thorough physical examination. On your cat’s blood work, your veterinarian may notice a decrease in the number of white blood cells. If your cat’s blood is examined under a microscope, your veterinarian may see abnormal white blood cells containing large granules. In some cases, a tissue biopsy (to look for abnormalities in skin pigment cells called melanocytes) may be required to diagnose Chediak-Higashi syndrome.
Currently, there is no readily available genetic test available for Chediak-Higashi syndrome. Cats that carry the gene can only be identified if they are bred to another carrier and produce one or more offspring with the condition. Both parents of an affected cat are confirmed carriers of the gene for Chediak-Higashi syndrome.
How is Chediak-Higashi syndrome treated?
Most cats with Chediak-Higashi syndrome do not require treatment. These cats should, however, receive regular veterinary care to monitor their health status. Your veterinarian will likely use special care when performing blood draws or other procedures on your cat to prevent bleeding. If your cat is undergoing surgery, your veterinarian may suggest a pre-surgical platelet transfusion to prevent excessive bleeding. If you find yourself seeing a new veterinarian, it is best to inform them that your cat has a bleeding disorder so they can take appropriate precautions.
"If you find yourself seeing a new veterinarian, it is best to inform them that your cat has a bleeding disorder so they can take appropriate precautions."
Cats with Chediak-Higashi syndrome should be kept indoors to reduce their risk of trauma and subsequent bleeding, while also decreasing their exposure to infectious diseases. Additionally, keeping these cats indoors protects their eyes and skin from harmful effects of the sun that can occur due to their lack of normal pigmentation.
Affected cats should not be bred and parents of affected cats should be removed from breeding programs.
What is the prognosis for cats with Chediak-Higashi syndrome?
The prognosis for cats with Chediak-Higashi syndrome is good. Most affected cats have a normal lifespan.