Step 1 : Introduction to the question "5. This syndrome results in developmental delays and a characteristic facial and bodily appearance, and was named for the doctor who first described it in the 1860s. What is the name of this chromosomal disorder?"
...1. Down syndrome 2. Edwards syndrome 3. Pearson syndrome 4. Klinefelter's syndrome Down syndrome was named for John Langdon Down, the British doctor who first described the disorder in 1862. In a paper published in 1866, Down identified a group of children who were in his care in Earlswook Asylum in Surrey, England, as having a distinct form of intellectual disability that caused them to share a common appearance, which he termed as "mongoloid". Down was adopting the racial classification system pioneered by Johann Friedrich Blumenbach that was popular at the time, and probably never realized that his use of the term would spark a debate in the scientific community almost a century later. By 1959, the cause of the disorder had been identified by French geneticist J�r�me Lejeune as being due to the presence of an extra 21st chromosome, and by 1961, a group of geneticists petitioned a renowned medical journal to ask that the term "mongolism" be abandoned and replaced by something else, pointing out that "the increasing participation of Chinese and Japanese investigators in the study of the condition imposes on them the use of an embarrassing term". The editors of "The Lancet" agreed, and supported the term "Down's syndrome". Today, references to "mongolism" are rare, with most textbooks and scientific journals adopting the non-possessive "Down syndrome" or "trisomy 21" to refer to the disease.