A "darling" three-year-old girl suffering from a rare combination of illnesses is in desperate need of a bone marrow transplant to save her life, doctors have said.
Tia Pugh, who suffers from an extremely rare form of immune deficiency - STAT1 deficiency - is believed to be the only person in the world to have a tuberculosis-like illness called mycobacteriym malmoense at the same time.
Despite months of hospital treatment and tests, medics have said that her only chance of a cure is a bone marrow transplant.
But her unique background - her father, Nick, is from Worcester, and her mother, Yupa, is Thai with Cambodian heritage - may make finding a genetic match extremely difficult.
Her parents have called for people to sign up to the bone marrow register to help Tia - who loves Peppa Pig and the Muppets - experience a childhood "full of fun and joy".
"Tia is our darling little daughter and it is heartbreaking to watch her suffer like this," Mr Pugh said.
"Now that the doctors have identified what's wrong we can at last get moving on finding a cure.
"But we have to be quick, and that cure is out of our hands until we can find a match."
He added: "All I can say to the people out there is please help us however you can, by signing up to the register or setting up a recruitment event in your area.
"Think how you would feel if it was your daughter, or your son, and you needed a stranger to help them survive. Childhood is supposed to be full of fun and joy, and that's all we want for our Tia.
"Please help us help her, by signing up to the bone marrow register."
Doctors have tried different combinations of drugs to help Tia, who had a blood transfusion before she was two.
For months, she had to go to the hospital at 7am and 11pm every day to receive vital medicines.
Nurses visit her home daily at 11am and 3pm to help care for her, and Tia's mother has been trained to administer her antibiotics at home.
Tia, who "loves singing and dancing to Peppa Pig, the Muppets' Mahna-Mahna song and Fatboy Slim's Eat, Sleep, Rave, Repeat when she has the energy", is also fed through an intravenous tube each night.
Anthony Nolan, the UK charity which manages the bone marrow register, has urged people to sign up as donors, especially those of South East Asian and mixed-Asian heritage.
Henny Braund, Anthony Nolan chief executive, said: "Tia's situation is so difficult that it's hard to hear about.
"But it is precisely this kind of circumstance that Anthony Nolan was set up to help with. Over the last 40 years we have seen thousands of caring, selfless people put their names on the register and thousands of lives have been saved as a result.
"Now it is vital that we get the message out, especially to the South East Asian community, so that we can find a match for Tia as soon as possible. Please help however you can."
Every year in the UK, around 1,800 people in the UK need a bone marrow or stem cell transplant - usually their last chance of survival.
People from black, Asian, and ethnic minority backgrounds have a 40% chance of finding a suitable bone marrow donor, compared with White northern Europeans, who have a 90% chance.
Donations usually take place during an outpatient appointment, in a procedure that is similar to donating blood.
You can join the bone marrow register here
Visit Tia's dedicated Facebook page here
Additional reporting by PA