Breakthrough answers on rare disorder that delays children's first word

???

Madilyn Hunt has a genetic disorder so rare, that at the time she was born in 2002, there wasn't even a name for it.

Her mother, Kathy, just had a feeling that something was not right with her second-born daughter.

As Madilyn got older, other people started noticing it too.

When she was admitted to hospital at 14 months, the nurses were very concerned that she was not making enough sounds.

By the time she was four or five, she could still only string a few words together. To communicate, she used a simple sign language called Makaton.

Kathy said while she noticed that her daughter was able to recognise letter and words, she struggled to verbally communicate what she felt.

"She went to kinder knowing all her colours and taught the other children their colours and how to sign their colours," she said.

It was not until Madilyn was about to start school in 2006 that researchers finally discovered the source of the problem, a deleted segment of chromosome 17.

They called it Koolen-de Vries syndrome.

Parents finally had the diagnosis, but questions remained about whether children affected could ever learn to talk and what their long-term prognosis was.

Now breakthrough Australian research published in The European Journal of Human Genetics indicates that some children with Koolen-de Vries, despite not saying their first word until age seven, should eventually learn to speak intelligibly.

The study looked at 29 people with Koolen-de Vries across the globe, including Australia. About one in 16,000 people worldwide are estimated to be affected by Koolen-de Vries, including approximately 300 Australian children.

The study found that while most of these children did not say their first words until around two or three, or even later, "remarkably" most will be able to speak by eight to 11 years - even if their words are a bit slurred, slow or imprecise.

"It is a really lovely, good news message," said the paper's co-author, Angela Morgan, a professor of speech pathology at the Murdoch Children's Research Institute.

"Later in primary school it does mean that the children will be able to develop speech. It's not perfectly clear but you can have a conversation with them and they are quite understandable.

"The parents are there waiting, desperately hoping that their kid is going to speak. Until this paper came out they didn't have any idea of the future prognosis."

While the disorder is marked by developmental delay and mild to moderate intellectual disability, the children are typically described as cheerful, sociable and cooperative.

"As a result they keep practising speech even though it is really challenging for them to overcome the severe oral weakness in life that prohibits early speech development," Professor Morgan said.

"They also tend to find powerful methods of communicating beyond spoken language ,such as using electronic devices."

The study highlighted the need for children with Koolen-de Vries to be enrolled in speech therapy early in life.

Madilyn is now 15 and attends the Ballarat Specialist School. She loves sports, colouring, singing the songs out of Mamma Mia! and slapstick comedy such as Mr Bean and Lano and Woodley.

The Hunt family spent many years anxiously waiting for her to speak.

"We so desperately wanted her to speak," Kathy said. "And now we have trouble getting her to not speak."

This story Breakthrough answers on rare disorder that delays children's first word first appeared on The Sydney Morning Herald.