Context: 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-Étienne Dominique Esquirol in 1838 and Édouard Séguin in 1844. In 1957, the genetic cause of Down syndrome, an extra copy of chromosome 21, was discovered.\n\nQuestion: where does the name down syndrome come from? Let's give stream of consciousness first:
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To answer this question, we should know that: It is named after John Langdon Down, the British doctor who fully described the syndrome in 1866.
So, the final answer is John Langdon Down.
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