London, June 18 (IANS) Legendary actor Warren Beatty's eldest daughter, Kathlyn Beatty is planning to undergo a sex change operation.

Kathlyn, 18, is living as a young man and has changed her name to Stephen Ira. Warren is shocked by his daughter's determination to change her gender, though he will not turn his back on her, reports dailymail.co.uk.

"Warren Beatty is beside himself over the situation with his daughter Kathlyn," said a source.

However, Kathlyn's mother Annette Bening who starred in "American Beauty", is trying to support her daughter as best she can, despite finding the situation heartbreaking.

"Kathlyn repeatedly told her parents that once she turns 18, she would take matters into her own hands. Her parents have tried to deal with this over the years when their daughter was younger, but she's determined to go ahead with the trans-gender operation, just as Chastity Bono," the source said.

Chastity Bono was born as a girl to singer Cher and husband Sonny. Bono underwent female to male gender transition, legally changing her name to Chaz and her sex to male.