Rubinstein-Taybi Syndrome with thymic hypoplasia

Area of Science:

• Pathology
• Immunology
• Genetics

Background:

• Rubinstein-Taybi syndrome and DiGeorge sequence are genetic disorders associated with developmental abnormalities.
• Thymic hypoplasia is a known feature of DiGeorge sequence, impacting T-cell development.
• Autopsy provides a critical opportunity to examine complex congenital anomalies.

Observation:

• Autopsy of a 20-month-old boy revealed no visible thymus.
• Microscopic examination identified severely depleted thymic tissue near the thyroid gland.
• Immunohistology confirmed the presence of T-cell surface antigens within the residual thymic tissue.

Findings:

• The patient presented with Rubinstein-Taybi syndrome and DiGeorge sequence.
• Significant thymic hypoplasia was confirmed, characterized by depletion of thymocytes and cortical epithelial cells.
• Associated anomalies included broad thumbs/toes, microphthalmia, arrhinencephaly, patent ductus arteriosus, ureterovesicular junction stenosis, and bilateral cryptorchidism.

Implications:

• Thymic hypoplasia likely contributed to the patient's recurrent respiratory infections.
• This case highlights the severe immunological consequences of combined genetic syndromes.
• Detailed autopsy findings are crucial for understanding the phenotypic spectrum and pathophysiology of complex congenital disorders.