Abby’s parents, Rae and Daniel, had no idea anything was amiss until she started to regress after turning 18 months old. ST PHOTO: BRIAN TEO

SINGAPORE – Four-year-old Abby was born healthy and met all her developmental milestones in the first 18 months of her life.

Her parents Rae, 41, and Daniel, 55 – who requested that The Straits Times not use their family name – had no idea anything was amiss until she started to regress after turning 18 months old.

Abby’s speech – from happy infant babbling to saying one or two words – suddenly halted in its development. Her movement and balance also regressed.

Her parents tried hydrotherapy to encourage walking. “We taught her how to walk in the pool, as we were told the water buoyancy would help her,” said Rae, who is an education consultant.

“The nursery school where we placed her also suddenly told us that it could not support a child with special needs. We decided to send her for tests,” Rae said.

Eventually, at three years and six months old, Abby was diagnosed with Rett syndrome, a rare brain disorder that affects mostly girls.

“We took blood for a DNA test, and it was only last August that Abby was confirmed to have Rett syndrome. Her care was transferred to KK Women’s and Children’s Hospital (KKH),” said Rae.

Before that, doctors had thought Abby was autistic.

“We did not know about Rett syndrome then, and we thought that she was autistic. Yet she was very sociable – she still is – and she loves people. Those are not (commonly perceived) traits of autism,” said Rae.

Rett syndrome is thought to affect about one in 15,000 to one in 10,000 female babies worldwide, but the exact prevalence is not known.

“Many patients with Rett syndrome may be undiagnosed due to lack of recognition of symptoms and limited access to genetic testing,” said Associate Professor Saumya Jamuar, a senior consultant with the genetics service at KKH.


Abby’s parents tried hydrotherapy to encourage walking. ST PHOTO: BRIAN TEO

Prof Jamuar noted that there have been only 10 cases diagnosed at KKH so far, with one or two patients identified every other year. But he cautioned that there could be others who are still undiagnosed in Singapore.

He said the condition is caused by a genetic change in a gene called MECP2. This gene provides the instructions for making the MeCP2 protein, which is important for brain development. Rett syndrome usually shows up in children between six months and two years old.

Affected children develop normally at first, but then begin to lose the skills they have already learnt, such as talking, walking or using their hands, said Prof Jamuar. Some may have seizures, heart issues or breathing difficulties. They could also have sleep disturbances and scoliosis, which is a sideways curvature of the spine.

A hallmark of Rett syndrome is near-constant repetitive hand movements or hand wringing – something Abby does.

“It is only when these symptoms appear that testing is considered. Even then, making a diagnosis requires a specific genetic test,” Prof Jamuar said.

“As the brain becomes more complex, it increasingly depends on the MeCP2 protein to support learning and retaining skills. The protein does not work in children with Rett syndrome and the brain cannot keep up with normal development... leading to loss of skills and other symptoms,” he said, adding that the severity varies from child to child.

Most patients have intellectual disability, with some experiencing only a mild form, he said.

There is currently no way to reverse Rett syndrome, and treatment focuses on managing its symptoms and supporting the individual.

A diagnosis marks the beginning of a coordinated, lifelong care plan involving multiple specialists and support services, said Prof Jamuar.

“The goals are to manage symptoms, support development, improve quality of life and prevent complications, to help each child reach her best possible quality of life,” he added.

“With appropriate care, many people with Rett syndrome live well into adulthood – some into their 40s, 50s, or longer.”

Rae went online to search for a local community of patients and found the Facebook and Instagram accounts of Rett Syndrome Singapore, set up by an expatriate mother with a daughter who has the condition.

“I messaged her and became one of the very few members of the community,” she said.

Rae also discovered that the condition is grouped under the Rare Disorder Society, a non-profit organisation initiated in 2011 by parents of children with lysosomal storage disorder, a rare genetic condition that causes a build-up of toxic materials in body cells. 

Abby now attends early intervention school at All Hands Together and will go to Rainbow Centre in July, where she will receive physical therapy, speech therapy and music therapy.


Education consultants Rae, 41, and Daniel, 55, using a photo chart to help their four-year-old daughter Abby express herself. ST PHOTO: BRIAN TEO

Unlike many other Rett syndrome patients, Abby is able to walk, though she cannot articulate most words.

Her movement “is not very stable” and she tends to fall and hurt herself, according to Daniel, who is also an education consultant. Trips to the emergency department at KKH are “becoming a regular thing”, he said.

“We also hired a physiotherapist and an occupational therapist to come to the house every week to help stabilise her movement and gait. She swims and rides her balance bicycle. Her speech therapist teaches her how to communicate with us. She uses her eyes and other gestures, which we learnt from her too,” he said.

Abby also suffers from seizures and is on medication to manage them.

Born in Hong Kong, Abby moved to Singapore with her parents when she was three months old.

Despite her limited verbal ability, she is exposed to a multilingual environment at home. Her parents and grandparents speak to her in English, Mandarin and Cantonese. “We also encourage our helpers to speak to her in Bahasa Indonesia”, said Rae.

Daniel added: “Abby is able to understand, but she just cannot reciprocate.”

The couple also have a one-year-old daughter, Emma, who was conceived before Abby’s diagnosis.

As Rett syndrome affects mostly girls, there were initial concerns that Emma might have the condition. “When Emma came along, we were of course worried. But when we saw her using her fingers to point at things – something that Abby could not do – we heaved a huge sigh of relief,” Rae said.

Prof Jamuar said although Rett syndrome is a genetic disorder, the majority of cases are not inherited, and the risk to Emma was low, at “approximately 1 per cent to 2 per cent”.

Meanwhile, research continues into future cures or gene-based therapies, with some promising results from animal studies. In these studies, symptoms were partially reversed by reintroducing the normal MeCP2 protein into the brains of mice, giving hope for potential treatment.

For now, the only word Abby can articulate clearly is “iPad”. “She repeats it when she is adamant. Sometimes I don’t know whether to laugh or cry, but we are taking this a day at a time,” said Rae.

Medical Mysteries is a series that spotlights rare diseases or unusual conditions.