Bruton's agammaglobulinemia

- X-linked recessive  inheritance (patients are BOYS)
- defect in BTK gene       --->      tyrosine kinase gene       --->    blocks pro-B-
    cells to form pre-B-cells.
- recurrent bacterial infections after 6 months because of low maternal IgG due to  
   opsonization defect.
- no thymic shadow
labs: 
- N pro-B-cells
- low maturation
- low B-cells
- low IGs all classes