<unk>  (also called<unk> -linked hypogammaglobulinemia,<unk> , Bruton type<unk>  is a rare<unk> -linked genetic disorder that affects the body's ability to fight infection (origin of the name: A=no, gammaglobulin=Antibody).<unk>  patients do not generate mature B cells. B cells are part of the immune system and normally manufacture antibodies (also called immunoglobulins) which defends the body from infections (the humoral response). Patients with untreated<unk>  are prone to develop serious and even fatal infections. Patients typically present in early childhood with recurrent infections, particularly with extracellular, encapsulated bacteria.<unk>  is an<unk> -linked disorder, and therefore is almost always limited to males. It occurs in a frequency of about 1 in 100,000 male newborns, and has no ethnic predisposition.<unk>  is treated by infusion of human antibody.  Treatment with pooled gamma globulin cannot restore a functional population of B cells, but it is sufficient to reduce the severity and number of infections due to the passive immunity granted by the exogenous antibodies.<unk>  is caused by a mutation on the<unk>  chromosome of a single gene identified in 1993 and known as Bruton's tyrosine kinase, or Btk.<unk>  was first characterized by Dr. Ogden Bruton in a ground-breaking research paper published in 1952 describing a boy unable to develop immunities to common childhood diseases and infections. Bruton's paper describes the first known immune deficiency.<unk>  is classified with other inherited (genetic) defects of the immune system, known as primary immunodeficiency disorders.
X-linked agammaglobulinemia
Combined immunodeficiency
Severe combined immunodeficiency
X-linked severe combined immunodeficiency
Common variable immunodeficiency
Primary immunodeficiency
Selective immunoglobulin A deficiency
Wiskott-Aldrich syndrome