A 1-year-old boy is brought to the office for medical evaluation. The patient was recently diagnosed with type 1 diabetes mellitus. He has also had chronic diarrhea, failure to thrive, and eczematous dermatitis since early infancy. Small bowel biopsy reveals villous atrophy and extensive lymphocytic infiltration. Immunologic testing shows significantly increased serum immunoglobulins and decreased IL-10 and transforming growth factor-beta levels. Genetic testing reveals a missense mutation affecting FOXP3. Which of the following is the most likely cause of this patient's current condition?

Question

A 1-year-old boy is brought to the office for medical evaluation.  The patient was recently diagnosed with type 1 diabetes mellitus.  He has also had chronic diarrhea, failure to thrive, and eczematous dermatitis since early infancy.  Small bowel biopsy reveals villous atrophy and extensive lymphocytic infiltration.  Immunologic testing shows significantly increased serum immunoglobulins and decreased IL-10 and transforming growth factor-beta levels.  Genetic testing reveals a missense mutation affecting FOXP3.  Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

Eductional Objective: FOXP3 is a transcriptional regulator protein that is required for the development of regulatory T cells; it triggers production of cytokines (eg, IL-10, transforming growth factor-beta) and ligands (eg, cytotoxic T-lymphocyte antigen-4) that suppress immune activation.  FOXP3 mutations result in immune dysregulation marked by excessive immunoglobulin production and the development of autoimmunity.

A 1-Year-Old Boy Is Brought to the Office for Medical