Velocardiofacial Syndrome (VCFS)
Description
Velocardiofacial Syndrome (VCFS), also known as DiGeorge Syndrome or 22q11.2 Deletion Syndrome, is a complex genetic disorder that affects various parts of the body, primarily the heart, face, and immune system. This syndrome is caused by a missing segment of chromosome 22, specifically the 22q11.2 region. VCFS can manifest with a wide range of symptoms, varying in severity from person to person. Understanding the intricacies of this condition is crucial for early diagnosis, appropriate management, and maximizing the quality of life for individuals with VCFS.
Genes Involved
VCFS is primarily caused by a deletion in the 22q11.2 region of chromosome 22. This deletion affects multiple genes, with some of the most commonly implicated genes including:
- TBX1: This gene plays a crucial role in heart development and facial formation.
- COMT: This gene is involved in dopamine metabolism, which can influence cognitive function and behavior.
- DGCR8: This gene is linked to the processing of microRNAs, small molecules that regulate gene expression.
Recognizing the Signs and Symptoms
Recognizing the signs and symptoms of VCFS is crucial for early diagnosis and intervention. These can include:
- Facial Features: A distinctive facial appearance, often characterized by a small chin, widely spaced eyes, a flat philtrum (the area between the nose and upper lip), and an upturned nose.
- Heart Defects: Congenital heart defects are common in VCFS, with Tetralogy of Fallot, ventricular septal defects, and patent ductus arteriosus being among the most frequent.
- Immune System Issues: Recurrent ear infections, respiratory problems, and a higher susceptibility to infections can be associated with VCFS.
- Learning Disabilities: Individuals with VCFS may experience learning challenges, including speech delays, language impairments, and difficulties with memory and attention.
- Behavioral and Psychiatric Concerns: Some individuals with VCFS may have behavioral issues, such as anxiety, depression, and attention-deficit/hyperactivity disorder (ADHD).
- Other Symptoms: Other possible symptoms can include cleft palate, hypocalcemia (low calcium levels), and gastrointestinal issues.
Causes
The primary cause of VCFS is a deletion in the 22q11.2 region of chromosome 22. This deletion can occur spontaneously during the formation of the egg or sperm, or it can be inherited from a parent who carries the deletion. In most cases, VCFS occurs randomly, with no known family history of the syndrome.
Inheritance/recurrence risk
VCFS is usually not inherited, as the deletion typically arises spontaneously. However, there is a small risk of inheritance if one parent carries the 22q11.2 deletion. The recurrence risk for future children is approximately 1-3% for parents who have already had a child with VCFS. Genetic counseling can help families understand their individual risk factors and make informed decisions about family planning.
