Scientists have developed a new stem cell technique for growing working liver cells, which could eventually avoid the need for costly and risky liver transplants.
A team of researchers led by the Sanger Institute and the University of Cambridge corrected a genetic mutation in stem cells derived from a patient's skin biopsy, and then grew them into fresh liver cells.
By putting the new liver cells into mice, they showed they were fully functioning.
The technique - the first success of its kind - leaves behind no trace of the genetic manipulation, except for the gene correction.
Stem cells are the body's master cells, the source for all other cells. Scientists say they could transform medicine, providing treatments for blindness, spinal cord and other severe injuries, and new cells for damaged organs.
The British team took skin cells from a patient with a mutation in a gene called alpha1-antitrypsin, which is responsible for making a protein that protects against inflammation.
People with mutant alpha1-antitrypsin are not able to release the protein properly from the liver, so it becomes trapped there and eventually leads to liver cirrhosis and lung emphysema.
This is one of the most common inherited liver and lung disorders and affects about one in 2,000 people of North European origin, the researchers said.
Having harvested the skin cells, the scientists reprogrammed them back into stem cells and then used a type of "molecular scissor" technique known as a zinc finger nuclease to snip the cells' genome at precisely the right place and insert a correct version of the gene using a DNA transporter called piggyBac.
The leftover piggyBac sequences were then removed from the cells, cleaning them up and allowing them to be converted into liver cells without any trace of residual DNA damage at the site of the genetic correction.
The results are being seen as a first step toward personalised cell therapy for genetic liver disorders.
The researchers said it could be another five to ten years before full clinical trials of the technique could be run using patients with liver disease. But if they succeed, liver transplants could become a thing of the past.