Laboratory Studies
The hair bulb tyrosinase assay has been used to differentiate between oculocutaneous albinism type 1 and the other forms of albinism. In this assay, scalp hair bulbs are gently plucked from the patient and placed in a 0.1% solution of L-dihydroxyphenylalanine (L-DOPA) for up to 4 hours. If the sample is from a patient with oculocutaneous albinism type 1 with mutations affecting the synthesis or catalytic function of tyrosinase, the hair bulbs remain white. In contrast, samples from all other forms of albinism turn dark during the incubation period.
For Chediak-Higashi syndrome, a confirmatory workup consists of analysis of a blood smear and the subsequent identification of neutrophils containing giant cytoplasmic granules.
For Hermansky-Pudlak syndrome, a confirmatory workup consists of electron microscopy of platelets and the subsequent identification of the absence of dense bodies (delta granules) and bleeding time determination that demonstrates a prolonged duration.
For Griscelli syndrome, confirmatory workup consist of immunological function evaluation plus both CT and MRI for neurological abnormalities.
These workups for albinism are not routine clinical tests.
Other Tests
In Chediak-Higashi syndrome, findings on electroencephalograms and electromyograms may be abnormal.
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Infant with oculocutaneous albinism type 1 presenting with hypomelanotic skin, white hair, and pink irides and pupils resulting from the dysfunction of tyrosinase in the melanocytes of these tissues and the subsequent lack of melanin synthesis. From Carden et al, Br J Ophthal, 1998, 82:189-195, with permission from BMJ Publishing Group.
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Neonate with oculocutaneous albinism type 3 presenting with minimally pigmented skin and light hair coloration resulting from the dysfunction of tyrosinase-related protein-1 in the melanocytes of these tissues and the subsequent reduction in melanin synthesis. The infant's parents are African American. From Carden et al, Br J Ophthal, 1998, 82:189-195, with permission from BMJ Publishing Group.
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Infant with Chediak-Higashi syndrome presenting with hypomelanotic skin and white hair with a metallic sheen. From Carden et al, Br J Ophthal, 1998, 82:189-195, with permission from BMJ Publishing Group.
