DiGeorge syndrome

DiGeorge syndrome
Updated: 08/16/2024
© Jun Wang, MD, PhD

General features
  • Inherited or sporadic
  • Multiple organ/tissue defects
  • Absence (complete) or underdeveloped (partial) thymus
  • Congenital heart disease most common cause of death
Clinical presentations
  • Facial appearance: Elongated face, retrognathia or micrognathia, cleft palate etc
  • Congenital heart defects
  • Neonatal hypocalcemia
  • T-cell dysfunction, although infections are not the first manifestation
  • Recurrent infections associated with T cell dysfunction: fungal, Pneumocystis jiroveci, viral, etc
Genetic abnormality
  • Deletion of 22q11.2
Pathogenesis
  • Failure of 3rd and 4th pharyngeal pouches
  • Heart involvement: Congenital heart diseases
  • Parathyroid defects: hypocalcemia
  • Thymus defect: No or deficient T-cell proliferation in response to mitogen
Key Laboratory findings
  • Reduced levels of T cells in peripheral blood
  • Severe T-cell deficiency in complete form
  • Hypocalcemia
  • Genetic studies (FISH) for 22q11.2
Key morphological features
  • Underdeveloped or absent T cells in lymphoid tissue
Diagnosis
  • Genetic studies: detecting the deletion
  • T-cell count and function
  • Immunoglobulin levels might be normal
  • Image studies for thymic and cardiovascular abnormalities
Managements
  • Cardiologist consultation
  • Vitamin D supplementation
  • Thymus transplantation, bone marrow transplantation
  • Treatments of infections and autoimmune complications



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Contents

Pathology notes Jun Wang, MD, PhD 1. General information Frequently discussed syndromes Terms of dermatology Terms of hematology 2. Primary immunodeficiency disorders 3. Hemodynamic abnormalities Shock Thrombosis and embolism Bleeding disorders 4.  Benign blood cell disorders Anemia Benign white cell disorders 5. Hematopoietic neoplasms Lymphoid neoplasms Myeloid neoplasms Histiocytic neoplasms: Langerhans cell histiocytosis 6. Cardiovascular system Pulmonary hypertension Cardiovascular system tumors 7. Respiratory tract tumors 8. Gastrointestinal tract Congenital disorders Infectious gastroenteritis Oral cavity Esophagus Stomach Intestinal tumors Salivary glands Exocrine pancreas and gallbladder 9. Urinary system Kidney masses Lower urinary tract 10. Male reproductive system 11. Female genital tract 12. Breast 13. Endocrine organs Pituitary gland Adrenal gland Thyroid gland Parathyroid gland Endocrine pancreas...
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Anemia

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