Caitlyn Jenner is to become a grandparent again.

Cassandra - who is known as Casey - is the reality TV star's second child with her first wife Chrystie Crownover, whom she was married to from 1972 to 1981 and with whom she also had her first son Burt Jenner, 37.

Caitlyn - who was known as Bruce before her gender transition last year - went on to have sons Brody, 32 and Brandon, 34, with second wife Linda Thompson, who she was married to from 1981 to 1986, and daughters Kendall and Kylie who are aged 20 and 18 years old respectively, from her third marriage to Kris Jenner, which ended last year.

The 66-year-old star previously confessed during an interview with American chat show host Diane Sawyer that she wasn't always there for Casey and her sons when they were kids because she was struggling to cope with her gender issues.

She said: "The big, formative years for them, I was really struggling with these issues. I talked to all of the boys about this after the fact, that, yeah, I didn't do a good job. And I apologised to my kids for that."

Meanwhile, 35-year-old Casey - who has two young daughters, Isabella and Francesca - is delighted that her relationship with Caitlyn has improved since her father transitioned.

She said last year: "My relationship with Caitlyn is much better than with Bruce... She's happier and more appreciative of her family. She is trying harder and there is a softness to Caitlyn that is new to me. I think part of that is that when someone is happier, they are just nicer."