Meet the sisters who have both been diagnosed with a one in 3.5 million condition, which is slowly turning their bodies to crystal.

Three-year-old Emily and her sister Poppy-Mae, 22 months, are among just 2,000 people in the world who have been diagnosed with the devastating disease cystinosis.

The incurable condition is a genetic disorder that causes a build-up of the amino-acid cystine in the cells of the body.

Over time cystine crystallizes in the cells, forming in the kidneys, the eyes, the thyroid gland and the liver. Without treatment, children with cystinosis are likely to experience complete kidney failure by about age 10.

In the past, it was rare for people with cystinosis to survive into adulthood.

But while the sisters will most certainly both face kidney transplants in later life, the brave children are facing their uncertain future together.

Their mother, Jessica Kemp, 25, from Leeds, U.K., said: “Basically their bodies are slowly being taken over by the crystals, which build up in their cells.

“Children with cystinosis don’t have the best life expectancies, but at least they each know what the other one is going through, and they will always have someone around to look after them."

Click here to read more on this story from The Sun.