Chromosomal mutations can have a variety of effects on individuals. Klinefelter syndrome is a genetic disorder that occurs when a male has an extra copy of the X chromosome. Males who have this disorder exhibit characteristics such as producing little or no facial hair, having a less muscular body than other males, and sterility. Karyotype of Klinefelter syndrome mc011-1.jpg Which type of chromosomal mutation causes Klinefelter syndrome? nondisjunction translocation deletion insertion