Detailed Instructions: Given a text passage, come up with an appropriate title for it. The title should accurately represent what the main focus of the passage is. The title of a passage may be present in the first few sentences of the passage and/or be referred to multiple times in the passage. The title should be 1-5 words long.
Q: Down syndrome is one of the most common chromosome abnormalities in humans . It occurs in about one per 1000 babies born each year . In 2015 , Down syndrome was present in 5.4 million individuals and resulted in 27,000 deaths down from 43,000 deaths in 1990 . It is named after John Langdon Down , the British doctor who fully described the syndrome in 1866 . Some aspects of the condition were described earlier by Jean - Etienne Dominique Esquirol in 1838 and Edouard Seguin in 1844 . In 1957 , the genetic cause of Down syndrome , an extra copy of chromosome 21 , was discovered .
A:
Down syndrome