Genetically edited sheep could help treat deadly childhood disease

Scientists have used a herd of gene-edited sheep to find a promising treatment for a deadly hereditary brain disease that affects young children. Researchers in the UK and US say their work could lead to the development of drugs to alleviate childhood Batten’s disease. Writes about it The Guardian.

In the UK, Batten’s disease affects between 100 and 150 children and young adults. It is inherited from two parents who carry this gene. The parents are in perfect health.

Children who carry two copies of this defective gene begin to suffer from vision loss, cognitive impairment, and mobility problems. They then go into convulsions and die. “The consequences for families are devastating,” said Professor Jonathan Cooper of the Washington University School of Medicine in St. Louis, one of the project leaders.

The researchers first began experiments working with colleagues at Collaborations Pharmaceuticals that showed that mice afflicted with a form of Batten’s disease, known as CLN1 disease, could be treated with the missing enzyme.

“It was encouraging, but we needed to test the treatment on larger brains with a structure more like a child’s brain,” said another project leader, Professor Tom Wishart from the Roslin Institute at the University of Edinburgh. It was at this university that Dolly the sheep was cloned for the first time in the world in 1996.

“You can’t directly extrapolate from mouse experiments to humans. It is very important to have an intermediate larger model,” the scientist said.

The project scientists used the Crispr-Cas9 gene editing method to create a version of the faulty gene responsible for CLN1 in sheep. “Sheep ovaries were collected from slaughterhouses, eggs were taken and fertilized. Crispr reagents were added to make the necessary changes in CLN1, and then the eggs were implanted in surrogate sheep.” The scientists were able to create a small herd of sheep, each of which was genetically edited to carry one functional copy of the CLN1 gene.

“These were asymptomatic carriers, as were the parents of children with Batten’s disease,” Wishart added. “Of these, we will breed sheep that have two defective copies. They develop a disease, like these children.” Research is ongoing.