Kourtney Kardashian has begged her fans to become bone marrow donors.

The reality TV star - who has two children, Mason, three, and Penelope, eight months, with her long-term boyfriend Scott Disick - issued an appeal in support of her cousin Cici, who urgently requires a transplant.

The 33-year-old beauty opened up about the tragic news on her blog on Tuesday (12.02.13), writing: ''My cousin Cici recently found out that after 17 years of battling cancer, her body has stopped responding to the chemotherapy and she desperately needs a bone marrow stem cell transplant.

''Because Cici is of Armenian descent she needs to receive bone marrow from an Armenian donor, which means the pool of options is a lot smaller and she's having a difficult time finding a match. We are asking that any of you who are Armenian, have Armenian friends or extended family members consider signing up as a donor at the bone marrow registry, in hopes that we can find a match for Cici and give our beloved cousin many more years to live.''

Kourtney explained that the procedure to donate marrow is quick and nonsurgical and is similar to giving blood.

She said: ''Because Cici is 100% Armenian the need for an Armenian donor is the most important. She has aligned herself with the Armenian bone marrow donor bank and you can get more info here: www.abmdr.am.''

The 'Kourtney & Kim Take Miami' star's appeal follows a similar one made by her younger sister Khloe, 28, earlier this month, who also begged fans to help her family.