By Jane Elliott
Health reporter, BBC News
Prakriti's sister donated bone marrow
Prakriti Virdi has needed monthly blood transfusions since she was four-months-old.
To avoid the transfusions causing a build-up of iron in her body, which could cause catastrophic organ damage, she had to sleep most nights with a medicine pump attached to her stomach for 12 hours.
She has beta thalassaemia major - where the body is unable to produce red cells containing normal haemoglobin to carry oxygen in the body.
Today, thanks to a bone marrow transplant from her sister Shagun, Pakrikiti is free of the medical procedures that have always ruled her life.
St Mary's Hospital in London, where she was treated, is a centre of excellence for treating children for non-malignant blood disorders like thalassaemia, sickle cell anaemia and bone marrow failure.
The children's bone marrow transplant centre (BMT) performs around 18 transplants a year and has a success rate of 97.7%.
But such successful outcomes have not always been the case.
When surgeons at the hospital carried out the operation in the mid 1980s the success rate was just 68%.
Now consultant Dr Josu de la Fuente said he can recommend the operation with an almost certainty of success.
"I can say to the families now that I can do BMT and that I am sure the child will be cured - something I could not say 10 years ago," he said.
Pakriti's mum Shalini said the operation had meant a new lease of life for her daughter.
"She was missing a lot of school. When she was young she did not realise what was happening, but as she grew up she saw others did not need to go to hospital like she did and started asking questions.
"You can't fully explain to them though.
"She would say things like 'why was I the only one out of all of us to be born with a genetic disorder' and in our extended family no-one had thalassaemia and we knew nothing about it.
"She was not in pain, but we feared the regular blood transfusions because there is an iron overdose risk.
"She had to have an injection in the stomach for 12 hours, which was very uncomfortable."
It is now around 18 months since Pakriti had her transplant at St Mary's, part of Imperial College Healthcare NHS Trust, and she is doing well.
But Shalini, from Hayes, Middlesex, said agreeing to transplant was not a decision the family took lightly.
"We got all the information we could and got information from the doctors and the internet - everywhere possible," she said.
Bone marrow transplants can offer a cure
"The staff are very nice and support you, but cannot tell you what will actually happen as every child is an individual, but they do give you the pros and cons.
"Her consultant, Dr Josu de la Fuente, said it was up to us as a family, but that if we went for the transplant it was going to be better for her life in the long run.
"So we decided on the transplant and are very happy with how things went."
Because there is a risk of death, St Mary's spend a year preparing families for the transplant operation with extensive psychological counselling, physical checks and home visits by a team of nurses, consultants, psychologists, dieticians and play specialists.
Dr de la Fuente, lead consultant at the stem cell transplant centre at St Mary's, said a transplant was the only treatment that can offer a long-term cure for blood disorders like Pakriti's if the patient has a suitable family donor, and the patient and family are willing to take the risk.
A transplant involves destroying the abnormal stem cells, which fail to produce normal blood, in a child's bone marrow and replacing them with healthy cells from a donor - often a sibling.
"The decision to have a transplant is a difficult one for the whole family," said Dr de la Fuente.
"We work closely with the families we treat to help them make an informed decision about their children's future.
"When transplant was originally developed, people did not think of these conditions because many of these children are not going to die immediately, such as was the case with leukaemia.
"But they do have a substantially reduced life span for thalassaemia. The current survival is only 75% at 35 years when receiving good treatment."
Quality of life
And he said that even those who do reach their 40s and 50s are likely to have significant damage in their organs.
"The transfusions that they have to receive cause severe damage in the liver, heart failure and damage in the pancreas causing diabetes.
"They also have a very reduced quality of life, not only because they have to go to hospital for their regular blood transfusions, but also because they have to take a lot of medication to reduce the iron that accumulates in the body."
Elaine Miller, of the UK Thalassaemia Society, cautioned that transplant was not always a consideration as everyone does not have a donor match.
And she said there were risks, including infertility for recipients.
"The decision of whether to pursue a bone marrow transplant is very difficult for the parents of children affected by thalassaemia, as thalassaemia is not a fatal illness - it is now very treatable (in the UK) and we have patients living into their sixth decade.
"Any parents considering this option should have access to extensive counselling before making a decision."