What are Klinefelter and Turner syndromes, respectively? And how do they differ

Klinefelter's syndrome is a genetic condition that only affects males. Affected males have an extra X chromosome. Males with Klinefelter's syndrome have small testes which do not produce enough of the male hormone testosterone before birth and during puberty.

Turner syndrome is caused by a missing or incomplete X chromosome. People who have Turner syndrome develop as females. Some of the genes on the X chromosome are involved in growth and sexual development, which is why girls with the disorder are shorter than normal and have incompletely developed sexual characteristics.