A 10-month-old kid is admitted to the hospital with respiratory distress caused by Pneumocystis jiroveci pneumonia. The kid has had many bouts of otitis media and thrush, and his weight is below the fifth percentile. An examination in the laboratory indicates normal levels of circulating B and T cells as well as low levels of all immunoglobulins. A uncommon autosomal recessive mutation results in a failure in the control of human leukocyte antigen gene transcription, according to genetic testing. The figure below depicts flow cytometry of the patient's peripheral blood compared to a healthy control: Which of the following processes is most likely to be impaired by this patient's mutation?

Question

A 10-month-old kid is admitted to the hospital with respiratory distress caused by Pneumocystis jiroveci pneumonia. The kid has had many bouts of otitis media and thrush, and his weight is below the fifth percentile. An examination in the laboratory indicates normal levels of circulating B and T cells as well as low levels of all immunoglobulins. A uncommon autosomal recessive mutation results in a failure in the control of human leukocyte antigen gene transcription, according to genetic testing. The figure below depicts flow cytometry of the patient's peripheral blood compared to a healthy control:  Which of the following processes is most likely to be impaired by this patient's mutation?

Quizplus · Accepted Answer

Eductional Objective: The HLA-DP, HLA-DQ, and HLA-DR genes encode MHC class II molecules, which deliver extracellular antigens processed in acidified lysosomes by antigen-presenting cells (eg, B cells, macrophages). MHC class II loss hampers B and T cell activation, resulting in a type of severe combined immunodeficiency.

A 10-Month-Old Kid Is Admitted to the Hospital with Respiratory