A 3-year-old child presents with recurrent staphylococcal skin infections, partial oculocutaneous albinism with silvery-gray hair, and easy bruising. A peripheral blood smear is ordered. Which finding is most diagnostic of Chédiak-Higashi syndrome?
Following phagocytosis, which of the following enzymes catalyzes the reaction of hydrogen peroxide with chloride ions to create hypochlorous acid in the phagosome?
A patient with suspected WHIM syndrome has a unique susceptibility to HPV-induced warts. Which additional finding is associated with this syndrome?
A child with a suspected complement deficiency has recurrent Neisseria infections. Deficiency of which complement component is most strongly associated with this presentation?
A 4-year-old with known X-linked hyper-IgM presents with severe neutropenia. Which of the following mutations could lead to severe neutropenia?
A child with a history of recurrent infections is found to have low serum levels of IgG, IgA, and IgM with normal B cell counts. What is the most likely diagnosis?
A patient is diagnosed with the idiopathic hypereosinophilic syndrome. Testing reveals that the patient had a clonal interstitial deletion on chromosome 4q12 that fuses PDGFR-α with FIP1-like-1 genes. What is the MOST appropriate treatment?
A 2-year-old with confirmed Chédiak-Higashi syndrome undergoes HLA-matched sibling hematopoietic stem cell transplantation prior to developing hemophagocytic lymphohistiocytosis. The transplant is successful with full donor chimerism. Which manifestation is LEAST likely to be corrected by this intervention?
A patient is diagnosed with autoimmune lymphoproliferative syndrome (ALPS). Genetic testing reveals a heterozygous mutation in the FAS gene. Which of the following best describes the pathogenesis of ALPS?
What laboratory test is most helpful to differentiate reactive neutrophilia from chronic myelogenous leukemia?
