Bruton (X-linked) Agammaglobulinemia
Bruton Agammaglobulinemia, also called X-Linked Agammaglobulinemia, is a X-linked recessive disorder that results in decreased B-cells and immunoglobulin levels. The causative mutation is on the BTK gene, a receptor tyrosine kinase needed for B-cell maturation. Clinical findings include absent tonsils or lymph nodes. Patients are therefore immunocompromised, which leads to increased susceptibility to infections by encapsulated bacteria. Finally, certain live vaccines like the MMR are contraindicated in these immunocompromised patients, because they could potentially lead to vaccine-related infections.