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Handbook of Genetic Counseling/Velo-Cardio-Facial Syndrome (VCF)

< Handbook of Genetic Counseling

Velo-Cardio-Facial Syndrome (VCF)

Introduction

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Elicit Medical History

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Elicit Family History and Pedigree

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What is VCF?

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  • 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

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  • 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

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  • 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

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  • 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 hypocalcemia 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

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  • 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

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  • 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

Psychosocial Issues

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  • Concern over what problems to anticipate with VCF
  • Parents may feel guilt or anger overdiagnosis
  • Confusion if mutation not found
  • Self-esteem issues for children with VCF due to learning disabilities
  • Social stigma due to speech difficulties

Resources

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  • "Faces of Sunshine: The 22q11.2 Deletion" Ed. Donna McDonald-McGinn, Brenda Finucane and Elaine Zackai. 2000.

References

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  • 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" .

Notes

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The information in this outline was last updated in 2002.

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