X-linked agammaglobulinemia is a rare genetic disorder that primarily affects males. It is caused by a mutation in the BTK gene, which is essential for the development of B cells, a type of white blood cell responsible for producing antibodies. Individuals with this condition have very low levels of immunoglobulins, making them highly susceptible to infections. Symptoms typically appear in early childhood and include recurrent bacterial infections, particularly in the respiratory and gastrointestinal tracts. Diagnosis is usually confirmed through blood tests that show low antibody levels. Treatment often involves regular infusions of immunoglobulin to help boost the immune system and prevent infections.