Chediak-Higashi syndrome Health Article

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.

Mutations have been found in the CHS1 (also called LYST) gene. The primary defect in this disease is in special granules present in skin pigment cells and certain white blood cells. For example, a granule that contains melanin is not made properly in skin, resulting in decreased skin 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
• Jerky eye movements (nystagmus)
• Increased infections in the lungs, skin, and mucous membranes

Infection 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)
• 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. Red light reflex of the eye, frequently seen in albinism, is present.

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