- Thrombocytopenia (bleeding)
What are the genetics?
What do the platelets look like?
What is the defect?
What are the usual presenting sx in infancy?
- Problem: results from mutations in WASP (intracellular signaling molecule
involved in T cell receptor signaling)
- X-linked recessive disorder (X chrom p11.22-23)
- recurrent infections
- defects in humoral and cell-mediated immunity, esp
recurrent sinopulmonary infections (PNA, OM) with encapsulated
organisms (S. pneumoniae, H. influenzae), in the first year of life
- opportunistic infections with P. jiroveci,
recurrent HSV (later)
- sepsis or meningitis due to encapsulated orgs, or opportunistic orgs.
- bleeding (due to thrombocytopenia)
- platelet counts in the range of 15 to 30 x 10^3/ mm3
- small platelets (think of Scott, a small asian, vs
a big St. bernard (bernard soulier - large platelets)
bleeding from circumcision site, or bloody diarrhea during infancy (usual
- at times, may be life-threatening (eg, intracranial hemorrhage).
- eczema - often seen before 6 mos of age; cutaneous findings are typical of atopic dermatitis,
although petechiae may be observed.
- Long term px (death by 6-11 years)
- Infections common cause of death
- Hemorrhage is a common cause of death
- Autoimmune cytopenias
- Increased risk of lymphoma and leukemia
- #1 cause of death= EBV-induced
- Labs: Decreased T cell numbers (CD3+, CD4+, CD8+) and function; low IgM
- Prenatal Dx: chorionicvillous sampling, amniocentesis
- Treatment: IVIG, BMT