Which of the Following Disorders is Not Caused by a Trisomy

Question

Which of the following disorders is not caused by a trisomy in human beings?
A) Down Syndrome
B) Patau's Syndrome
C) Turner's Syndrome
D) Edwards Syndrome
E) Triplo-X Syndrome

Accepted Answer

Turner's syndrome is caused by a monosomy (missing sex chromosome) rather than a trisomy (extra chromosome). Specifically, females with Turner's syndrome only have one X chromosome instead of the typical two.