Chediak-Higashi syndrome

Definition

Chediak-Higashi syndrome is rare, inherited disease of the immune and nervous systems characterized by pale-colored hair, eyes, and skin.

Causes, incidence, and risk factors

Chediak-Higashi is inherited, which means it is passed down through families. It is an autosomal recessive disease. This means that both parents must contribute a faulty gene for the child to show symptoms of the disease.

Mutations have been found in the CHS1 (also called LYST) gene. The primary defect in this disease is found in certain granules normally present in skin cells and certain white blood cells.

For example, in people with this disease, a skin granule that normally contains melanin is not made properly, resulting in decreased skin color (pigmentation). A defect in granules found in certain types of white blood cells causes immune system problems.

Symptoms

Children with this condition may have:

• Albinism -- silvery sheen to the hair, light-colored eyes
• Increased infections in the lungs, skin, and mucous membranes
• Jerky eye movements (nystagmus)

Infection of affected children with certain viruses, such as Epstein-Barr virus (EBV), can cause a deadly illness resembling the blood cancer lymphoma.

Other symptoms may include:

• Decreased vision
• Mental retardation
• Muscle weakness
• Nerve problems in the limbs (peripheral neuropathy)
• Nosebleeds or easy bruising
• Numbness
• Tremor
• Seizures
• Sensitivity to bright light (photophobia)
• Unsteady walking (ataxia)

Signs and tests

The doctor will perform a physical exam. Examination may show signs of a swollen spleen or liver or jaundice.

A blood smear shows giant granules in the white blood cells. Giant granules are also found in cells from biopsy of skin, muscle, and nerves.

Blood platelet or white blood cell counts are abnormally low. Genetic testing may show mutations in the CHS1 gene.

EEG may show seizures. Brain MRI or CT scan may show small brain due to atrophy.

EMG or nerve conduction velocity testing may show delayed nerve signaling. There may be decreased color (pigmentation) seen in the front and back of the eye.

Treatment

There is no specific treatment for Chediak-Higashi syndrome. Bone marrow transplants appear to have been successful in several patients, especially when performed early in the disease.

Antibiotics are used to treat infections. Antiviral drugs such as acyclovir and chemotherapy drugs are often used in the accelerated phase of the disease. Surgery may be needed to drain abscesses in some cases.

Support Groups

Chediak-Higashi Syndrome Association -- www.chediak-higashi.org

Expectations (prognosis)

Death often occurs in the first 10 years of life, from chronic infections or accelerated disease that results in lymphoma-like illness. However, some affected children have survived longer.

Complications

• Frequent infections especially with Epstein-Barr virus
• Lymphoma-like cancer
• Early death

Calling your health care provider

Call your health care provider if you have a family history of this disorder and you are planning to have children.

Call for an appointment with your health care provider if your child shows symptoms of Chediak-Higashi syndrome.

Prevention

Genetic counseling is recommended for prospective parents with a family history of Chediak-Higashi. Prenatal diagnosis may be available for this disease.

References

Boxer LA. Disorders of Phagocyte Function. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th Ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 129.