Final answer:
X-linked agammaglobulinemia, also known as Bruton's agammaglobulinemia, is a genetic disorder characterized by a deficiency in B cells and specific antibody production. The diagnostic criteria include recurrent infections, low or absent levels of immunoglobulins in the serum, and impaired B-cell maturation and differentiation.
Step-by-step explanation:
X-linked agammaglobulinemia, also known as Bruton's agammaglobulinemia, is a genetic disorder characterized by a deficiency in B cells, leading to a lack of specific antibody production. The diagnostic criteria for this condition include:
- Recurrent infections, especially with extracellular pathogens such as Haemophilus influenzae, Streptococcus pneumoniae, S. pyogenes, and S. aureus.
- Low or absent levels of immunoglobulins (antibodies) in the serum.
- Impaired B-cell maturation and differentiation, specifically a halt at the pre-B-cell stage of growth due to a mutation in the BTK gene.
This condition is inherited on the X chromosome, and its presence can be confirmed through genetic testing for the BTK gene mutation.