Disease_Mapped_To_Chromosome Human Chromosome 21 CPTAC Terminology GDC Terminology CPTAC Medical Conditions Codelist CPTAC Codelists Terminology Comorbidity Cellosaurus Disease Terminology Risk Factor GDC Value Terminology HL Medical History Table HL Authorized Value Terminology Syndrome Down Syndrome Trisomy 21 Syndrome CPTAC GDC Cellosaurus Down Syndrome A chromosomal dysgenesis syndrome resulting from a triplication or translocation of chromosome 21. This condition is characterized by distinctive facial and physical features: short stature, developmental delay, cardiac defects (atrioventricular septal defect, tetralogy of Fallot), hypo- and hyperthyroidism, autoimmune disease (type 1 diabetes mellitus), and hypogonadism. A chromosomal dysgenesis syndrome resulting from a triplication or translocation of chromosome 21. Down syndrome occurs in approximately 1:700 live births. Abnormalities are variable from individual to individual and may include mental retardation, retarded growth, flat hypoplastic face with short nose, prominent epicanthic skin folds, small low-set ears with prominent antihelix, fissured and thickened tongue, laxness of joint ligaments, pelvic dysplasia, broad hands and feet, stubby fingers, transverse palmar crease, lenticular opacities and heart disease. Patients with Down syndrome have an estimated 10 to 30-fold increased risk for leukemia; most have symptoms of Alzheimer's disease by age 40. Also known as trisomy 21 syndrome. Down Syndrome C2993 Down_Syndrome A disorder caused by the presence of an extra chromosome 21 and characterized by mental retardation and distinguishing physical features. Down syndrome PCDC Trisomy 21 C0013080 NICHD Trisomy 21 (Down Syndrome) Disease or Syndrome Down's Syndrome Down Syndrome Genetic Disorder NICHD Terminology Neonatal Research Network Terminology