A teenage girl started suffering from cancer symptoms when her identical twin was diagnosed in 2017 - despite not having the disease herself.
Sophie Walker, 16, was diagnosed with a Wilms' tumour - a type of kidney cancer - on October 25, 2017, and started a four-week course of chemotherapy shortly after.
In the five years since, she has gone into remission twice - but relapsed four times.
In the meantime, her twin sister Megan began experiencing many of the same symptoms, even though she does not have cancer.
After Sophie was diagnosed following stomach bug-like cramps, Megan began experiencing similar symptoms - including stomach and back pain, paleness as well as weight loss.
The girls' mum, Rebecca Walker, from Edinburgh, Scotland, said: "When Sophie was first diagnosed, Megan had all the symptoms. People comment on how ill she looks all the time - she's even paler than her sister.
"Every test under the sun has been done on her, and there's absolutely nothing wrong with her. It's so bizarre."
After an initial 27 weeks of chemotherapy, Sophie went into remission until January 2020 - when a routine MRI showed "something worrying" on her spine, the mum said.
A consultant informed Rebecca that her initial biopsy had seeded on her spine - meaning the needle inserted into Sophie's initial tumour had dislodged and spread cancer cells.
Following a three-week course of radiotherapy, a relapse in December 2021, and remission in December 2022, consultants told Sophie just three months ago that she'd once again relapsed.
Rebecca said: "We went to get Sophie checked out one day, and were told by the consultant she couldn't feel anything there.
"But by the following day, we were called back in. All the consultant could say was that the results were 'not good' - and she started to cry.
"Sophie saw the look on her face and just broke down, for the first time in six years."
Sophie's dad, Jamie Walker, 44, left the room with Sophie to console her - meanwhile Rebecca stayed with the consultant to ask further questions.
She said: "I was told to take her away and make memories, while she's well enough."
Since the news, Sophie's consultant has said she will be able to have the tumour on her spine operated on by a team of consultants, oncologists, pediatric surgeons and plastic surgeons.
Despite this "little bit of hope"' - Sophie is still struggling "deeply" with health anxiety and depression - and Megan has been feeling the "exact same way".
Rebecca said: "Megan just can't settle if Sophie isn't there. We have a big family and everyone looks out for each other, but Megan has been struggling hugely."
Sophie and Megan have eight siblings - James, 20, Emily, 19, Ruthie, 17, Daniel, 13, Olivia, 11, Emma, nine, Nathan, eight and eight-month-old Evan.
"While the older ones are looking after the younger ones in the house, Megan will stay in hospital by Sophie's side, sometimes until 3am," Rebecca added.
"She won't leave her until she says, 'I'm tired, I want to go to sleep.
"All throughout Covid, she wasn't allowed to see Sophie as Jamie and I were her two named visitors. She couldn't cope.
"As soon as those restrictions were slightly lifted, Megan wanted to see Sophie again."
When Sophie relapsed in January, Megan also volunteered herself for a "head-to-toe" MRI scan.
"Nothing showed up, there's absolutely nothing wrong with her," explained Rebecca.
"Consultants are telling me it's just a 'twin thing' - which I find totally bizarre. I've never heard of identical twins getting sick at the same time, when one isn't even ill herself."
The Walker family created a GoFundMe to raise funds for proton therapy in New York - after receiving surgery in Scotland on a date to be confirmed.
You can donate here.
