Cure for genetic diseases a step closer

Scientist have developed a method to turn cells from patients into mutation-free stem cells that can treat genetic diseases for which there is currently no cure.

"Right now, there are no cures for mitochondrial diseases," said senior author Juan Carlos Izpisua Belmonte, professor at Salk Institute for Biological Studies in California, US.

Mitochondrial diseases are caused by any of 200 mutations that affect the genes of mitochondria, tiny powerhouses inside nearly every cell of the body.

Depending on the affected genes and cell types, the diseases can cause muscle weakness, liver disease, diabetes, seizures, developmental delays or vision problems.

Existing therapies aim to ease the symptoms or slow the progression of the diseases, but cannot entirely cure them.

"We have developed ways to prevent these diseases, so it was natural to next ask how we could treat them," Belmonte said.

The researchers collected skin samples from patients with mitochondrial encephalomyopathy or Leigh Syndrome, both severe disorders that affect the brain and muscles.

In the study published in the journal Nature, the researchers described a method to generate stem cells even from patients who do not have cells with enough -- or any -- healthy mitochondria to start with.

For now, the researchers can use the healthy cells to generate heart, brain, muscle or eye cells from the mutation-free stem cells.

But methods to make those cells fully mature and functional and transplant them into patients are still under development, the study said.