For centuries, people with Down syndrome have been alluded to in art, literature and science. It wasn't until the late 19th century, however, that John Langdon Down, an English physician, published an accurate description of a person with Down syndrome. It was this scholarly work, published in 1866, which earned Down the recognition as the "father" of the syndrome. Although other people had previously recognized the characteristics of the syndrome, it was Down who described the …showed first 75 words of 154 total…

…showed last 75 words of 154 total…and separate entity. Throughout the 20th century, advances in medicine and science enabled researchers to investigate the characteristics of people with Down syndrome. In 1959, the French physician, Jerome Lejeune, identified Down syndrome as a chromosomal anomaly. Instead of the usual 46 chromosomes present in each cell, Lejeune observed 47 in the cells of individuals with Down syndrome. It was later determined that an extra partial or complete 21st chromosome results in the characteristics associated with Down syndrome.