Which of these chromosomal anomalies was the earliest to be described?

Ans. C. Trisomy 13Trisomy 13 was first described by Thomas Bartholin in 1657; trisomy 18 was first described by John Hilton Edwards in 1960; trisomy 21 was first described by John Langdon Down in 1866; and Turner syndrome was first described by Henry Turner in 1938.