Summary about Disease
DiGeorge syndrome (DGS), also known as 22q11.2 deletion syndrome, is a genetic disorder caused by a missing small piece of chromosome 22. This deletion leads to the improper development of several body systems. It's characterized by a wide range of symptoms and severity, affecting the heart, immune system, parathyroid glands (which regulate calcium levels), and facial features. It can also cause developmental delays, learning disabilities, and behavioral issues.
Symptoms
Symptoms vary greatly from person to person. Common signs and symptoms include:
Heart defects: Congenital heart conditions, such as tetralogy of Fallot or interrupted aortic arch.
Immune deficiency: Frequent infections due to a poorly developed or absent thymus gland.
Hypocalcemia: Low calcium levels in the blood, leading to muscle spasms, seizures, or heart rhythm problems.
Distinct facial features: Small jaw, wide-set eyes, low-set ears, cleft palate or other palate abnormalities.
Developmental delays: Speech and language delays, learning disabilities.
Feeding difficulties: Due to heart defects or palate problems.
Behavioral and mental health issues: Attention-deficit/hyperactivity disorder (ADHD), anxiety, autism spectrum disorder, schizophrenia (in adulthood).
Kidney abnormalities: Can range from mild to severe.
Causes
DiGeorge syndrome is almost always caused by a deletion of a small segment of chromosome 22, specifically at the 22q11.2 location. This deletion occurs near the time of conception, but it is not always inherited.
New Mutation: In most cases, the deletion occurs randomly and is not inherited from a parent.
Inherited: Less commonly, a parent with 22q11.2 deletion syndrome can pass the deletion on to their child. In this case, the child has a 50% chance of inheriting the syndrome.
Medicine Used
Treatment focuses on managing the specific symptoms a person experiences. Medications commonly used include:
Calcium and Vitamin D supplements: To treat hypocalcemia.
Antibiotics and Antivirals: To treat and prevent infections due to immune deficiency.
Gamma globulin infusions: To boost the immune system.
Growth hormone: In some cases, if growth is impaired.
Medications for heart conditions: Diuretics, digoxin, and other heart medications may be needed.
Medications for behavioral or mental health issues: Stimulants for ADHD, antidepressants for depression, anti-anxiety medications.
Is Communicable
DiGeorge syndrome is not communicable. It is a genetic disorder caused by a chromosomal deletion, not an infectious agent.
Precautions
Precautions depend on the individual's specific symptoms and immune function. General precautions include:
Avoiding exposure to infections: Practicing good hygiene, avoiding sick contacts, and ensuring vaccinations are up-to-date (live vaccines may be contraindicated for those with immune deficiency - consult a physician).
Monitoring calcium levels: Regular blood tests to check calcium levels and adjust supplementation as needed.
Protecting the heart: Following a heart-healthy diet, exercising as tolerated, and adhering to prescribed medications.
Managing developmental and behavioral issues: Early intervention services, speech therapy, occupational therapy, behavioral therapy, and educational support.
Avoiding crowds: Especially important for those with weakened immune systems.
How long does an outbreak last?
DiGeorge syndrome is not an outbreak. It is a genetic condition that is present from birth. The symptoms persist throughout the individual's life, though their severity and management needs may change over time. There is no "outbreak" associated with this syndrome.
How is it diagnosed?
Diagnosis typically involves a combination of:
Physical examination: Assessing for characteristic facial features, heart murmurs, and other physical signs.
Medical history: Reviewing the individual's medical history, including any history of frequent infections, seizures, or developmental delays.
Blood tests: Measuring calcium levels, immune cell counts, and looking for the 22q11.2 deletion.
Fluorescent in situ hybridization (FISH) test: A genetic test to detect the 22q11.2 deletion.
Chromosomal microarray analysis (CMA): Another genetic test that can identify the deletion.
Echocardiogram: To assess for heart defects.
Immunological evaluation: To assess immune function.
X-rays: To check for thymic shadow.
Timeline of Symptoms
The timeline of symptoms can vary greatly. Some symptoms may be present at birth, while others may develop later in childhood or even adulthood.
Newborn period: Heart defects, hypocalcemia, feeding difficulties, distinctive facial features may be apparent.
Infancy and childhood: Frequent infections, developmental delays (speech, language, motor skills), learning disabilities, behavioral problems.
Adolescence and adulthood: Mental health issues (anxiety, depression, schizophrenia), autoimmune disorders, continued monitoring of heart and immune function. The specific progression depends heavily on the severity of the individual's condition and the effectiveness of their treatment plan.
Important Considerations
Early Diagnosis and Intervention: Early diagnosis and treatment are crucial to improve outcomes.
Multidisciplinary Care: Management requires a team of specialists, including cardiologists, immunologists, endocrinologists, geneticists, developmental pediatricians, speech therapists, and other healthcare professionals.
Genetic Counseling: Genetic counseling is recommended for families affected by DiGeorge syndrome.
Transition of Care: As individuals with DiGeorge syndrome grow older, careful planning is needed to transition them from pediatric to adult care.
Long-term Follow-up: Lifelong monitoring and management are often necessary to address potential complications.
Live vaccines: Should be avoided in patients with severe T-cell deficiency.