Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Immunodeficiency with recurrent infections Microplatelet thrombocytopenia Eczema Occurs only in males +++ General Considerations ++ Characterized by immunodeficiency, microplatelet thrombocytopenia, and eczema Results from mutations of the gene encoding WAS protein (WASP) at X11p WASP is a protein involved in the rearrangement of actin and is important in interactions between T lymphocytes and antigen-presenting cells +++ Clinical Findings +++ Symptoms and Signs ++ Common presenting symptoms include mucosal bleeding, bloody diarrhea, cerebral hemorrhage, and severe infections with polysaccharide-encapsulated bacteria Clinical presentation can vary from classic severe Wiskcott-Aldrich syndrome to mild thrombocytopenia without immunodeficiency, or X-linked thrombocytopenia, depending on the mutation Malignancies and autoimmune syndromes can develop over time +++ Differential Diagnosis ++ Idiopathic thrombocytopenic purpura Leukemia Myelodysplasia Drug adverse effect Infection +++ Diagnosis +++ Laboratory Findings ++ Low platelet count Small platelets Low or absent isohemagglutinins Reduced antibody responses to polysaccharide antigens (Streptococcus pneumoniae and Haemophilus influenzae) IgM may be low IgG is usually normal IgA and IgE are often high +++ Diagnostic Procedure ++ Diagnosis can be confirmed by genetic testing for a mutation of the WASP gene or by assessing WASP expression Genetic testing can also be used for carrier screening +++ Treatment ++ Infection prophylaxis with antibiotics (including trimethoprim-sulfamethoxazole for Pneumocystis jirovecii pneumonia) IVIg-replacement therapy for patients with deficient antibody responses Splenectomy to reduce thrombocytopenia has been helpful in some patients with X-linked thrombocytopenia, but it must be followed by antibiotic prophylaxis because of the increased risk of septicemia and sudden death Platelet transfusions should be avoided unless severe bleeding has occurred Finally, bone marrow transplantation using the best-matched donor offers the possibility of a definitive cure, but it is associated with morbidity and mortality +++ Outcome +++ Prognosis ++ Left untreated, survival beyond adolescence is rare +++ Reference + +Kersseboom R et al: Educational paper: syndromic forms of primary immunodeficiency. Eur J Pediatr 2011;170:295–308 [PubMed: 21337117] . Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth