When Seng Malai's second son began showing symptoms of a hereditary disorder, she thought she was cursed.

Key points: Haemophilia affects 1 in 5,000 males globally

Haemophilia affects 1 in 5,000 males globally Before Ms Devenish's work, Cambodia lacked facilities for blood disorders

Before Ms Devenish's work, Cambodia lacked facilities for blood disorders More than 1,000 children are now being treated country-wide

Haemophilia had already claimed the lives of her first son at just 3 months old and her younger brother at 12.

Sokmao's joints would swell to crippling levels, leaving him bedridden in their tiny rural home, unable to attend school. Small cuts would bleed endlessly. Cleaning his teeth would often cause his gums to bleed for days.

"I was so scared for my son but we had so little money, and every doctor we visited sent us away with nothing," Ms Seng said.

Finally, when Sokmao was 10, they found an answer through an Australian volunteer scientist and a simple blood test that took 15 minutes and 5 millilitres of her son's blood.

'Robyn don't bother'

After 10 years of chronic sickness, Din Sok Mao was diagnosed with haemophilia and began receiving treatment in 2006. ( ABC News: Tracey Shelton )

The test was administered by Robyn Devenish, who arrived in Cambodia from Perth in 2001.

Ms Devenish saw that aid groups and international funds were supporting HIV and infectious diseases like TB, but there was little interest in, and no local knowledge of, haematological disorders.

Hundreds of children like Sokmao were undiagnosed or misdiagnosed, receiving misguided treatments that were expensive and sometimes life-threatening.

"There was so much misdiagnosis and it used to break my heart that so many kids were dying," Ms Devenish said.

Haemophilia can cause crippling swelling of the limbs. ( Supplied )

Cambodia was still struggling to recover from the Khmer Rouge regime that decimated the population and infrastructure in the late 70s, targeting the educated — including all medical staff and doctors — for torture and execution.

The medical field was decades behind the technology and treatment available back home in Perth.

Ms Devenish trained staff all over Cambodia to test and treat blood disorders. ( Supplied )

"I thought the only way to change this is to stay and volunteer," she said.

While the Angkor Hospital for Children had a basic lab, the staff lacked knowledge and equipment, so the first goal was to set up blood testing facilities and improve lab management systems to ensure the results were accurate.

"The expat doctors I was working with were horrified. They said, 'Robyn don't bother. The Khmer doctors won't understand and we can't treat them,'" she said, adding that she could see children at the hospital she could help.

"So even though I had this opposition and no support I went ahead and got the reagents and started the testing."

Sokmao's case sparks national change in treatment

Sok Mao at the family home in Pursat. ( Supplied: Steve Harknett )

While Ms Devenish was training lab staff and doctors to test for and treat various diseases, young Sokmao was referred to the Disability Development Services Program.

Community worker Steve Harknett noticed immediately the swelling in Sokmao's knee was not a deformity. Suspecting a blood disorder, he took the boy to Ms Devenish.

A quick test confirmed Sokmao had haemophilia — a hereditary blood disorder affecting only males that prevents the blood from clotting, meaning even a minor cut could prove fatal.

Ms Devenish had already had several confrontations with well-meaning surgeons, who had tried to operate on boys with swollen knees like Sokmao's, mistaking the symptoms for osteomyelitis or polio.

She said of one case, "I had to just about have a fistfight with the doctor to stop the surgery."

At other hospitals, boys had died on the operating table as doctors were unable to stop the bleeding.

Dr Chean Sophal oversees the testing and treatment Ms Devenish established in Phnom Penh. ( ABC News: Tracey Shelton )

"There wasn't any treatment for haemophilia at that time," Ms Devenish said.

"But just to have a diagnosis is something — at least they know then not to play with knives and play football."

Ms Devenish was able to provide basic treatment by spinning down blood donations to separate the plasma, while Mr Harknett wrote to the Phnom Penh Post about Sokmao's case.

The resulting article caught the attention of Australian donor Paul Freer and Alfred Steingruber, who became Sokmao's sponsor, supplying factor VIII clotting agent from Austria. But there were many other cases to come.

Mr Harknett, Mr Steingruber and Ms Devenish take Sokmao and his mother for lunch in Phnon Penh in 2006. ( ABC News: Tracey Shelton )

"Based on global prevalence rates, we estimate about 2,000 cases in Cambodia with 30 more babies born with Haemophilia per year," said Dr Chean Sophal, who worked with Robyn as head of haematology at the National Paediatric Hospital (NPH) in Phnom Penh.

Ms Devenish, Dr Sophal and Mr Harknett took on a new struggle to establish the Cambodian Haemophilia Foundation so the country could receive international supplies of factor VIII.

"The publicity around Sokmao was really the catalyst for haemophilia being recognised and addressed for the first time in Cambodia," said Mr Harknett. "I don't think it's an exaggeration to say that he opened the door to so many other children getting treated in the country."

The foundation, now run by a young man diagnosed as a child by Ms Devenish, has 180 members.

Another crippling blood disorder revealed

Siblings Sokpin, 17, and Soknoun, 22, suffer from the growth-inhibiting disorder thalassemia. ( ABC News: Louch Sopheak )

Ms Devenish had noticed frequent cases of anaemia that were routinely diagnosed as iron deficiency, but she felt this could instead be thalassemia, a genetic haemoglobin disorder.

18-month-old thalassaemia patient Meng Leng receives her monthly blood transfusion. ( ABC News: Tracey Shelton )

Her studies revealed that around 40 per cent of the national population were carriers with 1 per cent suffering from severe forms of thalassemia which inhibit growth.

"If they do not receive regular blood transfusions they will not grow," said Dr Sophal, who is now managing around 250 thalassemia cases.

"They will not develop normally and they may die at a young age."

Since Ms Devenish established testing, around 1,000 Cambodians are now receiving treatment countrywide.

"She went many times to different provinces … where she trained all laboratory technicians there also, so she did a lot of job, a lot of things," Dr Sophal said. "It was very, very good to have her in Cambodia."

'I want to thank you for all of my life'

Sokmao receives treatment in hospital ( Supplied: Steve Harknett )

Over the next 12 years, Ms Devenish went on to raise almost half a million dollars to buy lab equipment, train staff and produce booklets in Khmer explaining to patients how they could manage their conditions — providing them with the answers they so desperately needed.

"The Cambodian staff were just like sponges taking it all in," she said.

"At the end of every year, I'd see something else terrible happening — like the haemophilia boys — and I'd think I have to stay longer to fix this or fix that."

Ms Devenish was awarded the king's medal for her work in Cambodia. ( Supplied )

After returning to Australia and fighting her own battle with cancer, Ms Devenish now plans to return to Cambodia with the Tabitha Foundation to help establish a hospital for women.

"Its going to be in the poor area of Phnom Penh where there are hundreds of thousands of factory workers who have no real access to health treatment," she said.

Meanwhile, back in Cambodia, her legacy continues to grow as more children are diagnosed each day as a result of the work and training she has given to local doctors.

For Sokmao — now 22 and working as a security guard in Phnom Penh — the result has been both life-saving and life-changing.

"After I had the medication, my life changed dramatically because I could go to school and I can do many other thing as well," he said.

"Before I couldn't walk but now I can run."

When he was first diagnosed in 2006, Sokmao drew a picture during a special lunch with Ms Devenish, Mr Harknett and Mr Steingruber — who remains his sponsor — with the words he echoed 12 years later: "I want to thank you for all of my life."