KAREN Houghton, the only sister of Kris Jenner, has died in San Marcos, California, at the age of 65.

Karen worked as a part-time nurse and as a writer, choosing to remain out of the spotlight.

Kris Jenner’s only sister, Karen Houghton, has died

The Hulu star had an up and down relationship with her siblingCredit: Getty

It is unclear what the exact circumstances of Karen’s death is, however, county officials are attributing it to natural causes at the moment, according to TMZ.

Kris, 68, took to Instagram to mourn the loss as she shared numerous photos alongside her late sibling.

“It is with the heaviest heart and deepest sadness that I share that my sister Karen passed away yesterday unexpectedly,” the reality star shared.

“My heart aches for my mom MJ and my niece Natalie and I pray that God guides us all through this difficult time. Karen was beautiful inside and out. She was the sweetest, kindest, the most sensitive and vulnerable and so so funny.”

“She always felt grateful and thankful for her life and treasured her family and friends and especially her beautiful daughter,” Kris continued.

“She holds such a huge part of my heart and I cherish every single memory we have together.”

“Karen’s passing is a reminder that life is so short and precious and tomorrow is never promised. We must tell those we cherish how much we love them. I love you my beautiful sister,” she closed.

Kardashian fans and friends were quick to respond to the tragedy, as Simon Huck wrote, “I’m so sorry Kris for your loss.”

“So sorry Mj and Kris – prayers,” another said, as a third reacted, “Sending my love.”

Kris and Karen’s parents are MJ and Robert Houghton, as the star’s late sister was born just three years after the famous momager.

Robert died in 1975 at the age of 43 following a car crash.

While many of the Kardashian family members appeared on the small screen and on social media over the years, Karen remained out of the spotlight, especially as the sisters had their ups and downs.

‘SHE’S GOT ISSUES’

In 2014, Karen opened up about their relationship to Radar, calling out Kris’ split with ex Caitlin Jenner, now 74, at the time.

Karen claimed Caitlyn “walked out” on Kris and said she’s “got issues right now.”

Karen also called her younger sister “crazy” on her personal Facebook that same year.

She even claimed Kris would not answer her phone calls, suggesting the mom-of-six had “changed” since becoming a huge star.

“I don’t care how much money you have or who you are; you’re my sister,” Karen told Radar in 2014.

“I’m not afraid of her. I can’t get to her anymore. But I guess it’s the money.”

“She’s a huge celebrity, and now she has changed,” Karen claimed at the time.

“I’m not saying good or bad. But I’ve seen what it can do to Kris… ever since she moved to L.A.”

However, the relationship seemed to changed for the better in Christmas 2019 when the Hulu star took a snapshot with Karen’s daughter, Natalie Zettel, during a family moment.

Karen shared her daughter with ex-husband Mark Zettel.

Despite the apparent truce, Karen did not make other appearances on Kris’ social media.

In addition to her daughter, Karen is survived by Kris, her mother MJ, nephew Rob, and nieces Kylie and Kendall Jenner, and Kim, Khloe, and Kourtney Kardashian.

… She holds such a huge part of my heart,’ Kris shared on InstagramCredit: Instagram/KrisJenner

Karen remained out of the spotlight unlike her famous sisterCredit: Instagram/KrisJenner

Despite their ups and downs, Kris and Karen seemed to be on good terms in 2019Credit: Instagram/nataliezettel