DiGeorge Syndrome (22q11.2 Deletion Syndrome): A Comprehensive Overview
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a genetic disorder caused by the deletion of a small segment of chromosome 22. This deletion affects the development of multiple organ systems, leading to a wide range of medical and developmental issues.
Overview and Terminology
DiGeorge syndrome falls under the umbrella term of 22q11.2 deletion syndrome, encompassing conditions previously considered distinct, such as velocardiofacial syndrome. Despite variations in presentation, these conditions share the common feature of a missing segment on chromosome 22.
Symptoms and Clinical Manifestations
The symptoms of DiGeorge syndrome vary widely in severity and can affect various body systems. Manifestations may include:
- Cardiac Issues: Structural heart defects like ventricular septal defects, tetralogy of Fallot, or truncus arteriosus.
- Immune System Complications: Hypoparathyroidism due to underdeveloped or absent parathyroid glands, leading to calcium imbalances and compromised immune function.
- Cleft Palate: An opening in the roof of the mouth that can affect feeding and speech.
- Distinctive Facial Features: Including underdeveloped chin, wide-set eyes, hooded eyelids, and an enlarged nasal tip.
- Developmental Delays: Delayed motor skills, speech development, and cognitive delays.
- Behavioral and Emotional Issues: Such as ADHD, autism spectrum disorders, and anxiety disorders.
- Other Medical Problems: Including hearing loss, kidney abnormalities, skeletal differences, and autoimmune disorders.
Diagnosis and Management
Diagnosis of DiGeorge syndrome often involves genetic testing to confirm the 22q11.2 deletion. Early diagnosis is crucial for managing associated medical issues and developmental delays. Treatment typically involves a multidisciplinary approach, including:
- Cardiology: Management of heart defects and monitoring for cardiovascular complications.
- Endocrinology: Treatment of hypocalcemia and other endocrine abnormalities.
- Immunology: Monitoring and management of immune system function and susceptibility to infections.
- Speech and Language Therapy: Interventions to address feeding difficulties, speech delays, and communication issues.
- Psychological and Behavioral Support: Addressing developmental and behavioral challenges through therapies tailored to individual needs.
Causes and Risk Factors
DiGeorge syndrome is usually caused by a spontaneous deletion of chromosome 22 during early fetal development, often not inherited from parents. Rarely, a parent with a chromosomal rearrangement may pass the deletion to their child.
Prevention and Genetic Counseling
Genetic counseling is recommended for families with a history of DiGeorge syndrome or known chromosomal abnormalities. Understanding genetic risks can help families make informed decisions about family planning and prenatal testing.
Conclusion
DiGeorge syndrome is a complex genetic condition that requires lifelong management across multiple medical specialties. Early detection and comprehensive care can significantly improve outcomes and quality of life for individuals affected by this syndrome.
Sources:
- Mayo Clinic. DiGeorge Syndrome (22q11.2 Deletion Syndrome). Retrieved from Mayo Clinic Website
- Genetics Home Reference. 22q11.2 deletion syndrome. Retrieved from Genetics Home Reference
