Chédiak-Higashi Syndrome
Patient Information
Characteristics
Background and History
This form of hypopigmentation, or albinism, was described over 50 years ago. It has other, more severe, manifestations, however, such as difficulty fighting infections and neurologic disease. It is named after the Cuban physician, Alexander Moisés Chédiak, and Otokata Higashi, a Japanese pediatrician.
Clinical Correlations
The hair is light in color and the iris, or colored part of the eye, is often blue. The retina inside the eye is also light in color and many patients are light sensitive. Nystagmus, or dancing eyes, is common and can be responsible for below normal vision. Patients are susceptible to recurrent infections, particularly in the skin and gums. The white blood cells responsible for fighting infections are reduced in number and do not function normally. Many patients develop enlargement of their lymph glands, liver, and spleen. Many patients do not live beyond 3 to 4 years of age and those that do often develop difficulty with balance and walking. There may also be sensory deficits such as position sense and touch. Easy bruising and excessive bleeding is often noted as well.
Genetics
Inheritance
This is an autosomal recessive disorder which requires two mutations for expression. One of these comes from each parent who are called carriers and do not have disease.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
The lack of pigmentation is present at birth and can be diagnosed by pediatricians, ophthalmologists, and dermatologists. Bone marrow transplants can prolong life but eventually most patients develop neurologic disease. Individuals may also develop leukemia and a type of lymphoma.
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