A 7-year-old Chinese girl, Wang Yue, was diagnosed with osteopetrosis, a life-threatening disorder where bones become denser throughout the body.
Symptoms of the disorder include fractures, low blood cell production and loss of cranial nerve function which ultimately lead to blindness, deafness and facial nerve paralysis, reports World of Buzz and China Press.
Despite her condition, Wang Yue refuses to go for modern medical treatment as she wants her parents to spend the money on treatment for her one-year-old sister, who also suffers from the disorder.
While osteopetrosis patients can be cured with bone marrow transplants, the family could only raise enough money for one of their daughters to undergo the procedure which costs about 500,000 yuan (S$102,030).
Realising that only one of them can be saved, Wang Yue told her father: "Since we cannot manage to borrow so much money, I won't go for the treatment.
"I have some savings too, so you can take it and add it to the pool for sister's treatment fees."
She added: "I'm big already so it doesn't matter if I don't go for the treatment."
Her heartbroken father cried when he realised that Wang Yue was sacrificing herself for her sister.
The family's tragic circumstances have received attention nationwide with a fund-raising effort being set up.
Hopefully, with enough help, the two sisters will be able to grow up together.