Living with a rare brain disorder that affects mostly girls

Four-year-old developed normally for the first 18 months of her life before starting to regress

- Judith Tan

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 Sunday 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.