Digeorge Syndrome (22q11 Deletion)

Digeorge syndrome, also known as 22q11 deletion syndrome, is a rare genetic disorder caused by a deletion of a small part of chromosome 22. This condition is characterized by a range of physical, developmental, and immune system abnormalities.

Causes

The 22q11 deletion occurs when a segment of the long arm (q arm) of chromosome 22 is deleted. This deletion can occur in one of two ways: either as a result of a new mutation during fetal development or as an inherited condition from a parent who carries the deletion.

Symptoms

The symptoms of Digeorge syndrome can vary widely, but common features include:

• Heart defects, such as tetralogy of Fallot, truncus arteriosus, and interrupted aortic arch
• Cleft palate or velopharyngeal insufficiency (VPI)
• Immunodeficiency due to thymic hypoplasia or aplasia, leading to increased susceptibility to infections
• Hypocalcemia (low calcium levels) due to parathyroid gland dysfunction
• Facial abnormalities, such as a long face, prominent forehead, and small ears
• Developmental delays and learning disabilities
• Potential for psychiatric disorders, such as schizophrenia and anxiety disorders

Diagnosis

Digeorge syndrome is typically diagnosed through a combination of:

• Physical examination and medical history
• Genetic testing, including fluorescence in situ hybridization (FISH) or chromosomal microarray analysis (CMA)
• Imaging studies, such as echocardiogram and chest X-ray, to evaluate heart defects
• Immune system function tests, such as flow cytometry and immunoglobulin levels

Treatment

Treatment for Digeorge syndrome is focused on managing the individual's specific symptoms and preventing complications. This may include:

• Surgical repair of heart defects and cleft palate
• Thymus transplantation or immunoglobulin replacement therapy to address immunodeficiency
• Calcium and vitamin D supplementation to manage hypocalcemia
• Speech and language therapy to address communication difficulties
• Psychological support and counseling to address developmental and emotional challenges

Prognosis

The prognosis for individuals with Digeorge syndrome varies depending on the severity of their symptoms and the effectiveness of treatment. With proper management, many people with this condition can lead active and fulfilling lives.

Epidemiology

Digeorge syndrome is estimated to occur in approximately 1 in 4,000 to 1 in 6,000 births. It affects both males and females equally and can occur in individuals of all ethnic backgrounds.