Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Williams syndrome Deletes the gene for elastin and other neighboring genes at 7q11.23 Duplication of chromosome 7q11.23 results in a syndrome that includes speech delay and features of autistic spectrum disorders Smith-Magenis syndrome Associated with microdeletion of 17p11 Duplication of 17p11 produces Potocki-Lupski syndrome Velocardiofacial syndrome (Deletion 22q11 syndrome) Duplication of the 22q11 region produces a mild and highly variable phenotype that ranges from developmental delays and learning disabilities to functionally normal Also known as DiGeorge syndrome Originally described in newborns with cyanotic congenital heart disease, usually involving Great vessel abnormalities Thymic hypoplasia leading to immunodeficiency Hypocalcemia due to absent parathyroid glands +++ Clinical Findings ++ Williams syndrome Characterized by Short stature Congenital heart disease (supravalvular aortic or pulmonic stenosis) Coarse, elfin-like facies with prominent lips Hypercalcemia or hypercalciuria in infancy Developmental delay Neonatal irritability evolving into an overly friendly personality Natural history includes Progression of cardiac disease Predisposition to hypertension and spinal osteoarthritis in adults Mild to moderate intellectual deficits Smith-Magenis syndrome Characterized by Prominent forehead Deep-set eyes Cupid-shaped upper lip Self-mutilating behavior Sleep disturbance Intellectual disabilities Some patients also have seizure disorders, hearing loss, thyroid disease, and immunological and lipid abnormalities Potocki-Lupski syndrome is characterized by Growth failure Variable levels of cognitive deficiencies Autistic features Structural abnormalities of the heart (occasionally) Velocardiofacial syndrome (Deletion 22q11 syndrome) Characteristics include Mild microcephaly Palatal clefting or incompetence Speech and language delays Congenital heart disease (great vessel abnormalities, tetralogy of Fallot, and a variety of other abnormalities) Some affected individuals are predisposed to psychosis +++ Diagnosis ++ Suspected on the basis of an abnormal phenotype Confirmed via microarray +++ Treatment ++ Williams syndrome Calcium restriction may be necessary in early childhood to prevent nephrocalcinosis Smith-Magenis syndrome Velocardiofacial syndrome (Deletion 22q11 syndrome) GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. Access My Subscription GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessPediatrics 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessPediatrics Full Site: One-Year Individual Subscription $595 USD Buy Now View All Subscription Options