Pearson Syndrome: how one family learned to live in the present

Ruby Marshall is five years old. Her favourite colours are pink, green, and purple, and she adores her teddy bear, Minnie, as well as her dogs, Bobby and Monty.

In many ways, Ruby’s life is like that of any other child her age - she goes to school, plays with her friends, and is surrounded by a loving family. Her home in Lancaster is full of energy and warmth, shared with her mum Nikki, her dad, and her three siblings, who together create a lively, close-knit family life.

Nikki describes Ruby as feisty and bursting with energy - often calling her a “cheeky monkey,” just like many mums do with their little ones.

While Ruby enjoys many of the same joys and routines as other children, she is remarkable in a way that sets her apart - she lives with a rare health condition called Pearson Syndrome.

Ruby Marshall in her dazzling princess era

What is Pearson syndrome?

Pearson syndrome (also called Pearson marrow–pancreas syndrome) is a very rare mitochondrial disorder, affecting fewer than one in a million people worldwide. Mitochondria are structures inside our cells that produce energy, which our bodies need for our organs and tissues to function properly.

In Pearson syndrome, large deletions in mitochondrial DNA disrupt this energy production - especially in parts of the body that need a lot of energy. The condition usually starts in infancy and is often very serious and life-threatening, although symptoms can vary from person to person.

One of the main issues is in the bone marrow, where blood cells are made. This can cause pancytopenia, meaning low levels of red blood cells, white blood cells, and platelets. As a result, a child’s body may not be able to carry oxygen efficiently (anaemia), they may be more prone to infections, and they may bruise or bleed more easily.

The pancreas is also commonly affected. When it doesn’t work properly, it can lead to issues digesting food and absorbing nutrients, which can cause poor growth and weight gain.

In some cases, children who survive early childhood may later transition into another, closely related mitochondrial condition called Kearns–Sayre syndrome (KSS). As the disease evolves, it typically causes progressive muscle weakness, drooping eyelids (ptosis), vision and hearing loss, and neurological challenges. KSS can also affect the heart’s electrical system, leading to dangerous heart blocks that often require a pacemaker.

Nikki first noticed that Ruby’s development was different from other babies when she was around six months old.

“She was born in February, and in June we went to Devon for a week on holiday,” she recalls. “She was being sick all the time. At first, I thought it was colic or a bit of reflux, but she was also incredibly tired and seemed generally unwell.”

The following September, a visit to some family friends led to a trip to a day health centre after Ruby developed a urinary tract infection (UTI). Although she was given antibiotics and her symptoms mostly eased, Nikki suspected something was still wrong.

“Her colour was really yellow - something I’d noticed when she was born - so we took her back to the doctor, who then sent us to the hospital,” she says. “When we were in the hospital, they did a blood test and found her red blood cell count was incredibly low. She got a blood transfusion straight away, and then we were rushed to Manchester by ambulance.”

Nikki notes that although Ruby had a bone marrow biopsy, it didn’t reveal anything conclusive. After two or three more blood transfusions to bring her red blood cells back up, she was discharged, pending further tests over the next few months.

“They thought she might have something called transient erythroblastopenia of childhood (TEC), which is really rare and means the bone marrow can temporarily stop working,” Nikki explains. “I was hoping it was just a blip and that things would get better. But after each transfusion, her red blood cells would drop again - first after around ninety days, then every four weeks. She constantly needed blood transfusions.”

The following January, about seven months after her symptoms began, Ruby was finally diagnosed with Pearson Syndrome.

Nikki describes her first encounter with the condition in Manchester the previous December.

“I Googled it and found that some children with it don’t live past three or four,” she says. “But because she was eating and seemed relatively okay, I hoped it wasn’t that. It was very difficult when the diagnosis finally came through. I wish she’d been diagnosed sooner because then she could have had medicine to help her in those early years.”

Nikki describes Ruby as being able to do many activities that children with Pearson syndrome often struggle with. This includes eating solid foods without the use of a feeding tube - although it can still take her one to two hours to finish a meal.

Ruby has a fantastic support network around her, and her quality of life is supported by attentive family, friends, and medical professionals. An important part of that support is her daily medicine routine.

Nikki explains that Ruby no longer requires blood transfusions, which stopped when she was nearly three after her bone marrow began to improve. She currently takes several medicines to manage the effects of her disease. These include calcium folinate to support energy production in her brain, hydrocortisone to replace stress-related cortisol, levothyroxine for thyroid function, and Exjade to reduce previously elevated ferritin levels from earlier transfusions.

“She takes her medicines in the morning with her milk,” says Nikki. “Then we start breakfast, which takes around an hour. Because she needs to eat as much as she can to keep her energy up, she basically gets to eat whatever she wants. She’s even got a massive box of Lindt balls, wine gums, and lots of other sugary treats next to her bed because eating is her biggest challenge.

"Ruby needs roughly twice as many calories as a typical child, but can often only manage about a quarter of that. If she doesn’t eat enough, it usually means a trip to the hospital for a glucose drip to keep her energy levels up.”

After breakfast, it’s time for school, which Ruby enjoys. She has lots of friends there and takes part in lessons, playtime, and meals alongside her classmates.

“School have been fantastic,” says Nikki, her gratitude unmistakable. “They’ve been such a great support. Her teacher sits with her at lunchtime to make sure she’s eating enough and taking her medicine properly. We always send her in with plenty of snacks.”

Although Ruby enjoys a full school day, she is exhausted by the time it ends. Once the bell rings, she is taken home for tea and bed - but not before another dose of medicine.

Nikki explains that activities such as after-school clubs are usually out of the question. By then, Ruby’s energy reserves are depleted, and she will often fall asleep in the car on the journey home. For now, she is able to lead a full life - but it comes with clear limitations.

The average life expectancy of a child with Pearson syndrome is relatively short. Around half of children diagnosed with the condition do not survive beyond the age of three or four, and most do not reach their sixth birthday. While there have been rare cases of people living into their teenage years and beyond, such outcomes are exceptionally uncommon. Even for those who do survive longer, the progression of Pearson syndrome into KSS often brings a new set of debilitating long-term health challenges.

Although coming to terms with Ruby’s diagnosis was emotionally difficult, Nikki finds comfort in the fact that there is no single path that the disease must follow.

“Ruby’s got Pearson syndrome,” she says. “But she’s got - for want of a better term - one of the milder cases. I can’t change what’s happening, but I can hope for something better than the worst-case scenario.

“I’m so grateful that we’re getting a childhood with her. Mid-childhood is typically when symptoms begin to ramp up. But I’d rather focus on the years we have her relatively well than spend my time worrying about what might come later.”

Nikki cherishes the moments when she can still watch her daughter bounce on the garden trampoline or play games with her friends and siblings.

“It’s amazing that she can even read - that’s not something I ever envisaged,” she adds.

“So emotionally, we’re okay for now. But I know it’s going to be incredibly tough in the future when she can’t join in with things the way she does today. I don’t think she’ll make it to secondary school.”

Ruby has received a great deal of support from her family, and in turn, her presence in their lives has been a constant source of joy and meaning. Alongside friends and relatives, the family has also drawn on support from outside sources, including medical professionals and community groups.

Nikki speaks highly of the community nurses who supported her during the first year of Ruby’s blood transfusions. Over time, familiar faces became a reassuring presence, and it was comforting to see people they knew during what was often a difficult routine.

When the transfusions eventually stopped and the visits came to an end, Nikki realised just how significant that support had been.

“There wasn’t any real emotional clinical support after that, so, in hindsight, I felt a bit let down,” she recalls. “You still have so many concerns and worries, and there’s nobody to mentor you or guide you through life after diagnosis.

“I was paranoid that Ruby wasn’t walking or talking or doing what she was supposed to do. I think it would’ve been nice for somebody to sit me down and reassure me.”

Sisters uniting to raise awareness

The outlook for children with Pearson syndrome is very uncertain, and many experience significant health difficulties throughout childhood. Even if Ruby reaches her teens or early twenties, Nikki is aware that her daughter's quality of life will be severely affected.

Nikki believes that more serious symptoms may begin to emerge around the age of eight.

“It’ll probably start with her eyesight and hearing going, and she has a high chance of developing diabetes,” she says. “Even if she makes it to her early to mid-teens, at that point, she’ll most likely not be able to go to school anymore. At that stage, her condition is likely to evolve into KSS.”

Nikki notes that one of the most difficult aspects of Pearson syndrome is not only that Ruby’s life expectancy is short, but that the condition itself is continually changing. Symptoms can shift so quickly that, rather than living in a fixed state of decline, families are instead in a constant state of vigilance, never quite knowing what might happen next in the short term.

“The bottom line is that it really does force you to live for the day a bit more and do the things you might not have bothered to do,” she reflects. “However, it’s also okay to just sit and appreciate the little things. They’re incredibly important - it’s about celebrating the ordinary.

“We were so happy when Ruby started school, and I’m always amazed by everything she does. It brings these little euphoric moments over the smallest things. One of the most precious things to me is my journal, where I write about things Ruby has done or said. It’s really helped the last few years feel longer and more full.

“Everything she does feels really magical. It’s teaching us the meaning of life, in a way - albeit a painful one, I suppose.”