A Pakistani couple who lost their six-month-old daughter to pneumonia have spoken of their fear after learning that their second child had a life-threatening genetic disease.
Shayan Arif, 35, and his wife Noor ul Ain Khan, 29, had never heard of immune deficiency when their son Hamdan became ill at six months.
Their daughter, Hamda, had died in Oman in 2023 after spending 22 days in hospital with a severe infection.
No underlying genetic condition was diagnosed at the time, but two years later, as doctors investigated a prolonged fever suffered by Hamdan, his parents were told he could have an immune deficiency.
“The first statement the doctor told us was that it was a life-threatening disease,” Mr Arif said. “That was the first thing: life-threatening.
“Obviously, it was very, very scary because we had already lost our daughter.”
Genetic testing later showed Hamdan had a rare RAG1-related immunodeficiency and Omenn syndrome, a condition that severely affects the body’s ability to fight infection.
Doctors now suspect that the couple’s daughter might have suffered from the same inherited disease. She had been healthy until she developed a fever when she was about six months old.
“We thought maybe it was a regular fever, so we went to a clinic,” Mr Arif said.
“They checked her and said it was fine. They gave her regular medicine for the fever and said, ‘Inshallah, she’ll be fine.’”
But the fever persisted and Hamda developed a serious chest infection and pneumonia. She was admitted to hospital where she died, 22 days later.
“At that time, it was not diagnosed,” Mr Arif said. “No one told us we should go for genetic testing.
“We thought maybe she got an infection and the doctors couldn’t find out what it was. We said, ‘She’s gone, she’s gone. Now we have to move forward.’”
The couple moved to the UAE about two weeks after their daughter’s death, when Mr Arif, who works in information technology, was transferred for work.
Hamdan was born in Sharjah in April 2025, following a normal pregnancy.
“He was very healthy,” Mr Arif said. “For the first five months, everything was regular.”
Hamdan's fever
At about five months old, Hamdan developed a rash and an infection, but initially recovered after treatment.
About a month later, he developed a fever. Doctors initially believed he had a routine infection and prescribed antibiotics and medicine.
But after about 10 days, the fever had not improved and his family were advised to take him to hospital. He was eventually admitted to another hospital in Sharjah, and when his temperature came down, he was discharged. But the fever returned the same night.
Hamdan was readmitted the following day, by which time he had been suffering from a fever for more than 20 days. Doctors started him on steroids and began investigating abnormal findings in his immune system.
It was during that admission that his parents first heard the words “immune deficiency”.
“It was very shocking because we were not aware of that disease,” Mr Arif said. “They asked us about our other child and we told them about our daughter,” Mr Arif said. “That was when they thought there could be something genetic.”
The warning about the seriousness of the condition stayed with Hamdan’s parents.
“When he was born, somewhere in the back of our minds we thought we had to be very careful with him. We had already lost our daughter. And suddenly you hear that the baby has this kind of disease,” Mr Arif said.
Doctors advised the couple to keep Hamdan away from public places while they waited for the genetic results. “From that time, our isolation started,” he said.
The results arrived near the end of February and confirmed an inherited immune deficiency.
The couple began searching for treatment immediately and thought they might have to travel abroad for a bone marrow or stem cell transplant.
They considered options including India, Thailand and Europe before being referred to Yas Clinic and Abu Dhabi Stem Cells Centre.
“We immediately took an appointment and met Dr Mansi,” Mr Arif said. “Obviously our question to her was: ‘Will he be fine?’ She said: ‘Consider it done.’”
Dr Mansi Sachdev, a consultant in paediatric haematology, oncology and bone marrow transplantation at Abu Dhabi Stem Cells Centre, said Hamdan had a rare form of immunodeficiency caused by mutations in the RAG1 gene.
“Immunodeficiency means that the immunity of the child is really low,” she said. “He had one particular type of mutation that he was carrying, called a RAG1 mutation, and it is a genetic problem because both parents are carriers.”
The condition means the immune system cannot function normally, leaving affected children unable to fight infections effectively.
Hamdan had also developed Omenn syndrome, a severe manifestation of an immune disorder.
Dr Sachdev said his skin had become extensively red and inflamed, and he had enlarged lymph nodes in his neck, armpits and elsewhere on his body. He had also developed several viral infections while being treated at other hospitals.
“Especially when you have this disease and you’re not treated at the right time, it can lead to death,” she said. “Sometimes kids die as early as two months or three months if they have a life-threatening infection. Sometimes they do live up to one year or two years.”
Transplant donor
Hamdan did not have a sibling who could act as a donor, but both his mother and father were found to be half matches.
“We didn’t have much time, so we took the father as the donor for him and we did an urgent transplant,” Dr Sachdev said.
Although Mr Arif carries one copy of the altered gene, Dr Sachdev said carriers can still be suitable donors for this type of condition.
“If you have one gene that is working fine and the other gene that is not working fine, you’re OK.
“Both the mother and the father are OK. They are not having immunodeficiency. They’re just carriers.”
Hamdan was admitted for treatment in late April and underwent his transplant on May 8.
Before the transplant, he received chemotherapy to prepare his body for the donor stem cells. For his mother, seeing him after chemotherapy was one of the hardest stages of treatment.
“When I saw him after the chemotherapy, he was very weak,” she said. “There were so many new things happening. It was hard. We were very, very scared when we heard again that word ‘life-threatening’.
“And when you hear about the treatment – he’ll be having chemotherapy and then going through the transplant – and he’s a small baby, you think, how are we going to see him in this condition? That time was very difficult for us.”
Doctors had warned Hamdan's parents that he could initially become weaker following chemotherapy and transplantation, but over the following weeks, they began to notice an improvement.
“After four weeks, he started eating well. He started drinking well,” Mr Arif said. “After a month, we started seeing that he was getting better.”
Dr Sachdev said Hamdan, now 13 months old, is doing well. “He’s healthy,” she said. “He has accepted the donor cells. There is no complication. There is no graft-versus-host disease.”
He needs to avoid crowded public places for about six months after the transplant while his immune system recovers.
“Not isolated in terms of being bubble-wrapped, but going to a mall or grocery store or any crowded place should be avoided,” said Dr Sachdev.
Mrs Khan said she was now seeing her son return to himself.
“Now I’m happy,” she said. “He’s fine. He’s getting better. He plays better.”
Her husband said the family were relieved after months of uncertainty and fear.
“I’m very happy, very, very happy,” he said. “We went through this whole journey with very good doctors, a very good team.
“I’m very thankful, especially to Dr Mansi and her team and all the staff of this hospital. They really took very good care of him.”
Greater awareness
Hamdan is not the only young child with a severe immune deficiency to have received a transplant at the centre.
Dr Sachdev said the team had treated two other children with RAG1 or RAG2-related conditions, as well as a number of patients with other types of immune deficiency.
She said the number of cases being identified did not necessarily mean that rare immune deficiencies were becoming more common, but that doctors were becoming more aware of the conditions and were more likely to investigate when young children developed unusual or repeated infections.
“Physicians, especially general physicians, have started to think about rare forms of immune deficiencies when they see unusual infections,” she said.
“That’s how we are picking up these patients more and more now as compared to before.”
Family history can also provide an important clue. Dr Sachdev said Hamdan’s sister probably died without ever receiving a diagnosis.
“At that time, nobody thought about it,” she said. “But now, when we have something that has already happened in the family, when you tell physicians, then they realise that there’s something more to it.”
