Chédiak-Higashi syndrome
- Definition: defect in neutrophil chemotaxis and microtubule polymerization dysfunction → defective phagosome-lysosome fusion
- Etiology: autosomal recessive; defective lysosomal trafficking regulator (LYST) gene
- Clinical features
- Recurrent pyogenic infections
- Partial albinism
- Due to impaired melanocyte transport of melanin to keratinocytes in the epidermis and epithelial cells in the retina. Because melanin is also involved in the embryologic development of ocular structures (eg, optic nerve), reduced visual acuity and nystagmus may occur.
- Progressive degeneration of neurons and peripheral neuropathy
- Hemophagocytic lymphohistiocytosis (can occur in the accelerated phase and is potentially fatal)
- Diagnosis
- Peripheral smear shows giant cytoplasmic granules in granulocytes and platelets
- Mild coagulation abnormalities
- Pancytopenia (especially neutropenia)
- Peripheral smear shows giant cytoplasmic granules in granulocytes and platelets
Mnemonic
Chédiak-Higashi sounds like a mountain, where traffic are defected.