Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder of the immune system characterized by chronic infections, neutropenia, partial oculocutaneous albinism, and bleeding diathesis with partial neuropathy. The disease usually appears during infancy or childhood, and proves fatal in many of the patients in the first decade of their life. Progress to the accelerated phase of the disease is usually precipitated by a viral infection. When expressed first in adults, the disease usually takes a much milder course. Typical symptoms include nystagmus, decreased vision, and photophobia, albinism, a silvery sheen to the hair, increased cutaneous, oral and respiratory infections, ataxia, and peripheral neuropathy.
Diagnosis is made on the basis of clinical symptoms, and additional tests. Giant, peroxidase-positive granules can be seen in the WBCs, as well as in the skin, muscle, and nervous cell biopsies. WBCs show an abnormally low level, and the spleen and liver may be enlarged. Other findings include seizures on EEG, small, atrophied brain on MRI, and delayed nerve conduction on EMG. Treatment mostly involves administration of antibiotics or antiviral therapy to cure the infection. No specific cure for the underlying pathology is available. However, bone marrow transplants have been successful in some patients.
CHS arises from mutations in the Lysosomal Trafficking Regulator (LYST) gene on chromosome 1. LYST is involved in the sorting of endosomal resident proteins into late multivesicular endosomes by a mechanism involving microtubules.
