Handbook of Genetic Counseling/Velo-Cardio-Facial Syndrome (VCF)
Velo-Cardio-Facial Syndrome (VCF)
Introduction
- Who referred you here today?
- What specific questions would you like to have answered today?
- What information have you already been given?
What is VCF?
- VCF is an alternate name used in past literature for the condition currently referred to as 22q11 Deletion Syndrome.
- A highly variable syndrome of associated anomalies including congenital heart disease, dysmorphic features, palate anomalies, and some degree of learning disabilities or mental retardation
- Children with VCF often have feeding problems and speech problems
Etiology and Natural History
- VCF occurs in about 1/4000 live births
- About 90% of people with VCF have a deletion at 22q11.2
- Most cases are a result of a new mutation
- In 10-20% of cases one parent also has a deletion and VCF phenotype
Recurrence Risk
- Children of those with VCF have a 50% chance of inheriting the deletion
- Parents of a child with a new mutation have a very low risk of having another child with the mutation
Clinical Features
- Heart Defects
- Congenital heart disease occurs in about 74% of patients
- These defects are generally conotruncal defects
- Tetrology of Fallot - 22%
- Interrupted Aortic Arch - 15%
- Ventral Septal Defect - 13%
- Truncus Arteriosus - 7%
- Other Defect - 17%
- Palate
- Palatal Defects occur in 69% of patients
- Velopharyngeal incompetence (VPI) is the most common defect (27%)
- Disorder of the velopharyngeal valve which is required for normal speech
- Can lead to hypernasal speech, nasal air emission, or other speech problems
- Submucosal and overt cleft palate are also common
- Feeding
- 30% of patients have feeding problems
- nasal regurgitation is the most common problem
- many feeding problems are a result of the palate defects
- Thymus
- Many patients (specifically those with diGeorge sequence have a dysplastic or absent thymus)
- This results in a decrease in T-cells leading to decreased immune response
- Absent thymus can also cause hypocalcaemia which may lead to seizures
- Dysmorphology
- A variety of dysmorphic features are associated with VCF
- Microcephaly
- Narrow palpebral fissures
- Wide nasal root
- Bulbous nasal tip
- Thin upper lip
- Micrognathia
- Short stature
- Eye and ear abnormalities
- Neurological Defects
- Most patients have some degree of learning disabilities or mental retardation
- Intelligence generally in low normal range
- Often have language difficulties
- Specifically with reading comprehension and expressive language
- Other associations
- Kidneys: may be polycystic or dysplastic
- Growth: may be smaller in some cases due to lack of growth hormone
- Rheumatoid Arthritis: more frequent than general population
Molecular Testing
- Chromosomal region is called DGCR
- FISH analysis can be used to identify a deletion on chromosome 22
- Chromosome analysis should be run at the same time in order to locate the occasional disruption caused by a translocation of part of 22
Management
- Monitor heart function
- Repair defects if necessary
- Evaluate palate
- Intervention for feeding problems
- Repair of palate if necessary
- Monitor blood calcium levels
- Renal ultrasound to check kidneys
- Monitor lymphocytes
- Prevent use of live virus vaccines in patients with reduced immune response
- Provide speech therapy early in development
- Provide early intervention for school
- Concern over what problems to anticipate with VCF
- Parents may feel guilt or anger over diagnosis
- Confusion if mutation not found
- Self-esteem issues for children with VCF due to learning disabilities
- Social stigma due to speech difficulties
Resources
- "Faces of Sunshine: The 22q11.2 Deletion" Ed. Donna McDonald-McGinn, Brenda Finucane and Elaine Zackai. 2000.
References
- GeneClinics: 22q11 Deletion Syndrome
- Rommel, N., Vantrappen, G., Swillen, A., Devriendt, K., Feenstra, L., and Fryns, J.P. "Retrospective Analysis of Feeding and Speech Disorders in 50 Patients with Velo-Cardio-Facial Syndrome" Genetic Counseling. 10.1: 71-78, 1999
- Saal, Howard. Chapter 4: The Genetics Evaluation and Common Craniofacial Syndromes
- Cleft Palate and Craniofacial Anomalies: The Effects on Speech and Resonance Chapter 2: "Velopharyngeal Dysfunction (VPD) and Resonance Disorders" .