Lincoln team's 'stunning' result in fatal child disease research

A ground-breaking therapy is on the horizon for a lethal childhood disease after a research group at Lincoln University achieved stunning results in sheep.

Sheep also suffer from Batten disease, making them the perfect creatures for an experimental gene therapy now approved for use in children through the United States Food and Drug Administration.

An affected flock at the university includes one sheep which walks in circles and bumps into the paddock fence, even as researchers help it to follow the rest into a nearby field. It is not among the lucky ones to receive the gene therapy, so suffers the disease’s trademark blindness and cognitive decline.

Batten disease is a rare inherited neurodegenerative disorder. Children are completely healthy at birth but begin to lose their vision at a young age.

Their brain cells die away and they lose the ability to walk and talk. Most only live to their teens. One in four offspring of parents who are both carriers will develop the disease.

Research group lead Dr Nadia Mitchell is excited some affected children will soon be accessing the gene therapy via human trials in US. She has worked on the therapy for about 10 years.

Mitchell and fellow research team member, post-doctoral fellow Dr Samantha Murray, have met young patients and their families from around the world and attended conferences in Europe and the US.

They have been in touch with a Canterbury family who recently lost their second child to the disease. About four children are diagnosed in New Zealand each year.

“It’s just so thrilling because you meet these wonderful families that have been through horrendous things with their children,” Mitchell said.

“We really do it for them. And it’s so nice to treat the sheep and see them doing so well and successfully in the field.”

The gene therapy developed by the research team involves one-off injections to the brain and eyes with a virus carrying a copy of a missing gene. Sheep with Batten disease live to be only about two-years-old.

“We have animals in the field that are five years of age and doing really well,” Mitchell said.

“We can essentially halt the disease, so it’s not a complete cure, but it is definitely a treatment, and there’s currently not a treatment for Batten disease. And it may be that it is a cure, it may be that we are not seeing that playing out fully in sheep.”

The research team utilises a breeding flock of 200 ewes, descended from sheep discovered to have the disease on a Dunsandel farm about 20 years ago. They are healthy carriers and produce offspring that are either carriers or have the disease.

Murray said she and her fellow team members have become quite fond of their woolly charges, all of which have their own personalities.

They take about 15 of them on an annual weekend outing to St George’s Hospital for an MRI scan. The sheep are transported on a farm ute in two separate trips to the entrance, where team members are happy to explain to curious onlookers why they are bringing sheep to the hospital.

The sheep are then anaesthetised and trolleyed in one by one. Murray said they make sure no telltale strands of wool are left behind in the MRI chamber.

“We clean up after ourselves, we leave no trace that we have been there.”

The Canterbury Medical Research Foundation has been among the funders of the research, contributing more than $200,000. Marketing and communications manager Barbara Chapman said it was exciting to see the years of research culminating in human trials.

“It can take a long time to get to a specific point, but when you get to this point, it can have a real benefit on human health and well-being.”