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Foundation Sciences · Genetics

DiGeorge Syndrome (22q11.2 Deletion)

⏱️ 30 mins read 📖 Genetics 🎯 MLA Relevance: High

DiGeorge syndrome (22q11.2 deletion) is the commonest microdeletion syndrome; features include cardiac defects, hypocalcaemia, immunodeficiency, palatal anomalies and characteristic facies.

📌 Learning Objectives

  • Describe the underlying mechanism of DiGeorge Syndrome (22q11.2 Deletion).
  • Identify the key clinical features and complications of DiGeorge Syndrome (22q11.2 Deletion).
  • Outline the appropriate investigations and management of DiGeorge Syndrome (22q11.2 Deletion).
  • Discuss the implications for patients and families of DiGeorge Syndrome (22q11.2 Deletion).
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Curriculum Mapped
UK MLA Curriculum

📋 Overview

Mnemonic 'CATCH-22': Cardiac defects, Abnormal facies, Thymic hypoplasia (T-cell deficiency), Cleft palate, Hypocalcaemia, 22q11.2 deletion.

🔬 Basic Science

Mnemonic 'CATCH-22': Cardiac defects, Abnormal facies, Thymic hypoplasia (T-cell deficiency), Cleft palate, Hypocalcaemia, 22q11.2 deletion.

🏥 Clinical Relevance

T-cell function should be assessed; avoid live vaccines if severely immunodeficient.

🧪 Investigations

Investigation depends on clinical context: relevant blood tests, imaging, and specific genetic or histopathological tests as appropriate. Refer to specialist services where indicated.

💊 Management

Management is condition-specific and typically multidisciplinary, combining medical therapy, surgical intervention where appropriate, supportive care, and family/genetic counselling.

Revision Resources – expand the sections below for high-yield notes, exam pearls, key facts and further reading.

🎯 MLA High-Yield Notes & Quick Revision
Common SBA themes: recognising the underlying mechanism, identifying classic clinical features, and choosing the first-line investigation or management step. Watch for inheritance pattern and characteristic associations.
digeorge 22q11.2 catch-22 conotruncal thymic hypoplasia
  • DiGeorge syndrome is caused by 22q11.2 microdeletion.
  • CATCH-22 mnemonic: Cardiac, Abnormal facies, Thymic aplasia, Cleft palate, Hypocalcaemia.
  • Conotruncal heart defects (TOF, truncus arteriosus) are characteristic.
  • Hypocalcaemia results from parathyroid hypoplasia.
  • Most cases are de novo (not inherited).
Exam Pearls
⭐ High Yield
DiGeorge syndrome is caused by 22q11.2 microdeletion.
CATCH-22 mnemonic: Cardiac, Abnormal facies, Thymic aplasia, Cleft palate, Hypocalcaemia.
Conotruncal heart defects (TOF, truncus arteriosus) are characteristic.
Hypocalcaemia results from parathyroid hypoplasia.
Most cases are de novo (not inherited).
💡 Clinical Pearl
Digeorge: T-cell function should be assessed; avoid live vaccines if severely immunodeficient.
⚠️ Exam Tip — Common Mistakes
Confusing the mechanism of DiGeorge Syndrome (22q11.2 Deletion) with related conditions.
Missing classic clinical features of DiGeorge Syndrome (22q11.2 Deletion) in SBA stems.
Failing to consider DiGeorge Syndrome (22q11.2 Deletion) in the differential diagnosis.
🔑 Key Facts
DiGeorge syndrome is caused by 22q11.2 microdeletion.
CATCH-22 mnemonic: Cardiac, Abnormal facies, Thymic aplasia, Cleft palate, Hypocalcaemia.
Conotruncal heart defects (TOF, truncus arteriosus) are characteristic.
Hypocalcaemia results from parathyroid hypoplasia.
Most cases are de novo (not inherited).
🔗 Related Topics
📚 References
  1. GMC MLA Content Map
  2. NICE Clinical Knowledge Summaries
  3. BMJ Best Practice

Further Resources

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