Genetic counseling: 22q11 Deletion Syndrome

22q11 Deletion Syndrome (a.k.a. Velocardiofacial Syndrome (VCF), DiGeorge Syndrome)

Diagnosis
chromosome 22 (DGCR) deletion does not seem to correlate with severity of characteristics Characteristic Findings: and can be surgically repaired mouth to the esophagus pneumonia percentile in height narrow external auditory meati renal anomalies
 * Caused by a deletion of material from one copy of the long arm of
 * Submicroscopic deletion in DiGeorge Chromosomal Region
 * Chromosome banding may sometimes detect deletion
 * FISH testing detects deletion in 95% of affected individuals
 * Autosomal dominant inheritance
 * About 94% of patients have de novo mutation
 * Parents of affected individuals should have FISH testing
 * Offspring of affected individual have 50% chance of inheriting 22q11 deletion
 * Recurrence risk for siblings of affected individual is very small if FISH testing shows the parents do not have the deletion
 * Several genes are located within the DGCR
 * Some of these gene products have been identified
 * Cannot predict genotype-phenotype correlation because size of
 * Congenital heart disease
 * Found in about 74% of affected individuals
 * Usually conotruncal malformations
 * Teratology of Fallot
 * Interrupted aortic arch
 * Truncus arteriosis
 * Ventricular septal defect (VSD)
 * Conotruncal malformations identified in infancy/early childhood
 * Mild problems with the aorta may not be recognized
 * Palatal abnormalitites
 * Found in about 69% of affected individuals
 * Several types of abnormalities observed
 * Velopharyngeal incompetance (VPI)
 * Submucosal cleft palate
 * Visible cleft palate
 * Cleft lip and palate
 * Bifid uvulae
 * May be surgically repaired
 * May affect speech development
 * Speech therapy is recommended
 * Feeding difficulties
 * Found in about 30% of affected individuals
 * May be due to palate or heart problems
 * May also be caused by problems transporting food from the
 * Signs of feeding difficulty
 * Infants are irritable, gag, vomit, have a weak suck
 * Younger children find spoon feeding easier but have trouble drinking from a cup
 * Older children have difficulty with lumpy, crunchy foods
 * May be treated by teaching children better feeding practices
 * Immunodeficiency
 * Caused by small or missing thymus gland
 * Causes greatest number of problems in first year of life
 * Children may have frequent infections such as bronchitis or
 * As children grow older, T cell production improves
 * Hypoparathyroidism
 * Regulates calcium levels in bloodstream
 * Absence or underdevelopment leads to hypocalcemia
 * May cause tremors, seizures, muscle spasms, abnormal breathing, and abnormal heart rhythms
 * Diagnosed by a blood test
 * Treated with calcium supplements
 * Growth hormone deficiency
 * Approximately 41% of affected individuals are below the 5th
 * May be caused by abnormalities in formation of pituitary gland
 * In only about 1/10 of individuals with 22q11 deletion
 * Causes reduced levels of growth factors
 * Can be determined with a blood test
 * Treatment with injections of growth hormones
 * Characteristic Facial Features
 * Nose - bulbous nasal tip, prominent nasal root, nasal dimple
 * Ear - overfolded helices; cupped, microtic, and protuberant ears;
 * Eyes - hooding of upper or lower lid, ptosis, epicanthal folds
 * Renal anomalies
 * Found in about 37% of affected individuals
 * Includes single kidney, echogenic kidney, small kidneys, and other
 * Juvenile rheumatiod arthiritis (JRA)
 * About 150 times more frequent than in general population
 * Age of onset is 17 months to 5 years
 * Developmental difficulties
 * Found in 70-90% of affected individuals
 * Development of motor skills
 * Due to problems with muscle strength and coordination
 * Often delayed in sitting, crawling, walking
 * May be helped by physical therapy
 * Learning
 * Typically have slower learning rate
 * Follow same learning sequence as other children but at slower pace
 * Often have strong verbal skills but weaker math skills
 * May have difficulty paying attention
 * Early diagnosis and intervention important
 * May require learning support
 * Speech and language
 * Verbal speech usually does not develop until 2-3 years
 * May also have difficulty in formation of sounds
 * Palatal problems often lead speech problems
 * Early intervention by speech and language pathologist is important
 * Behavioral difficulties
 * About 40% of affected individuals develop psychiatric illness
 * Depression
 * Anxiety
 * Schizophrenia
 * Bipolar disorders
 * May be evident as tantrums and mood swings in childhood
 * Social skills training and counseling may be necessary

Resources

 * Cincinnati Velocardiofacial Support Group
 * Teresa Paul
 * 9327 Bluewing Terrace
 * Cincinnati, Ohio 45236
 * Email: MOTHERTP@aol.com


 * Velo-Cardio-Facial Syndrome Education Foundation
 * Jacobson hall Room 707
 * University Hospital
 * 750 East AdamsStreet
 * Syracuse, NY 13210
 * Phone: 315-464-6590
 * Email: vcfsef@hscsyr.edu
 * Web:


 * International DiGeorge/VCF Support Network
 * c/o Family Vioces of New York
 * 461/2 Clinton Avenue
 * Cortland, NY 13045
 * Phone: 607-753-1621 (day) 607-753-1250 (evening)


 * Chromosome Deletion Outreach, Inc.
 * PO Box 724
 * Boca Raton, FL 33429-0724
 * Phone: 561-395-4252
 * Email: cdo@worldnet.att.net
 * Web: