Which amendment banned discrimination between genders?
Do you mean voting rights???
19th Amendment (1920)
"WOMEN'S VOTING RIGHTS"
"The right of citizens of the US to vote shall not be denied or abridged by the US or by any State on account of sex..."
An Equal Rights Amendment banning discrimination of genders has been proposed, but has not passed.
The U.S. Constitution does not ban gender discrimination. As Bee said, the only close Amendment is the 19th that give women the right to vote.