Dallas Brown: Devonport boy living with TANC2, an almost unknown genetic mutation

An “everyday cheeky little boy” has finally received a diagnosis after years of seizures: a genetic mutation affecting perhaps only a few dozen globally. It’s raised more questions than answers.

An “everyday cheeky little boy” from Tasmania’s North-West who suffered two years of endless seizures has finally received a diagnosis: a genetic mutation that may affect as few as dozens of people worldwide.

The revelation that Devonport boy Dallas Brown, 4, who had his first seizure aged 18 months and now lives with a galaxy of conditions, possessed the TANC2 gene mutation, has raised more questions than answered.

Shanade Maroney, a childhood friend of Dallas’ mum Courtney, said she used to look after Dallas when he was a baby.

“He was a normal, average everyday cheeky little boy, but once this happened, he was a completely different child. You wouldn’t recognise him,” Ms Maroney said.

Devonport boy Dallas Brown, 4, who possessed the nearly unheard of TANC2 genetic mutation, with his mum Courtney and sister Haisley. Picture: Supplied

Among other conditions, Dallas lives with intractable epilepsy – up to 50 seizures a day, sometimes – speech and intellectual development delays, autism, hypotonia, ataxia, dysphasia and “all that comes with his mutation”.

“He can’t walk steady by himself. He’s very heavy now and is non-verbal too,” Ms Maroney said.

Dallas took a worrying turn for the worse at the start of last week, requiring ventilation and an induced coma, Ms Maroney said, although his condition has since stabilised.

Devonport boy Dallas Brown, 4, who possessed the nearly unheard of TANC2 genetic mutation. Picture: Supplied

“An X-ray showed he had chest and lung infection and pneumonia,” Ms Maroney said.

“His poor little body, his lungs collapsed when he was flown to Hobart. His heart rate kept spiking to 185, his blood pressure was really low.”

Dallas remains in Royal Hobart Hospital’s Neonatal and Paediatric Intensive Care Unit.

The strain on Courtney, an administration officer in the disability sector, and her husband, a FIFO mine worker, had been unimaginable, Ms Maroney said.

“It’s cost them an absolute fortune in different medications, equipment he needs – she has to watch him all the time. It’s just been chaos,” she said.

“(Dallas) has endured a life of unknown... and his family behind him every step making it work and searching for answers.

Devonport boy Dallas Brown, 4, who possessed the nearly unheard of TANC2 genetic mutation. Picture: Supplied

“They have endured a battle no parent should have to.”

Ms Maroney has established an online fundraiser to help Courtney and her husband, Dallas’ father, with medical costs. It has raised $2865 at the time of writing.

One all-encompassing question remains: Where on earth can the family find a neurologist with knowledge of the TANC2 mutation, of which there is little literature available.

There’s little support either. The Mercury could find a single TANC2 group on Facebook. Based in the United States, it has 51 members.

A 2019 study, published in Nature, considered 20 cases of patients with “likely gene-disrupting mutations in TANC2”.