Y is often used to feminize a variant spelling of a name, though of course there's nothing intrinsically gendered about it. The Karsyn spelling is slightly off its peak for girls, but rising for boys.

Karsyn debuted on the boys’ side of the US Top 1000 in 2018, sneaking in at number 940, but dropped off again in 2019. Karsyn for a girl continues to rise.