Down Syndrome

Down syndrome is a genetic disorder caused by an extra copy of chromosome 21, which disrupts brain/body development and causing characteristic physical and intellectual features. It occurs in 1/700 live births worldwide (3,000-5,000 children/year). Intellectual and developmental disabilities vary in severity, language/cognitive development delays, learning and attention problems. Down syndrome is typically diagnosed at birth through a blood test called a karyotype—and is the most common genetic cause of intellectual disability. People with down syndrome and their advocates form a neurominority.