X-linked agammaglobulinemia

X-linked agammaglobulinemia is a rare primary humoral immunodeficiency disorder caused by pathogenic variants in the Bruton tyrosine kinase gene, occurring almost exclusively in male infants and children

X-linked agammaglobulinemia is a rare primary humoral immunodeficiency disorder caused by pathogenic variants in the Bruton tyrosine kinase gene, occurring almost exclusively in male infants and children Pathophysiologically, the defect halts early B-lymphocyte differentiation in the bone marrow, resulting in a profound absence of circulating mature B cells and severely diminished or undetectable levels of all serum immunoglobulin classes

X-linked agammaglobulinemia is a rare primary humoral immunodeficiency disorder caused by pathogenic variants in the Bruton tyrosine kinase gene, occurring almost exclusively in male infants and children Following the clearance of maternally acquired antibodies during early infancy, affected individuals typically present with severe, recurrent bacterial and enteroviral infections—most commonly including otitis media, sinusitis, pneumonia, and gastrointestinal illnesses

Pathophysiologically, the defect halts early B-lymphocyte differentiation in the bone marrow, resulting in a profound absence of circulating mature B cells and severely diminished or undetectable levels of all serum immunoglobulin classes

Following the clearance of maternally acquired antibodies during early infancy, affected individuals typically present with severe, recurrent bacterial and enteroviral infections—most commonly including otitis media, sinusitis, pneumonia, and gastrointestinal illnesses