Researchers have provided new clues into the genetics underlying a chronic form of liver disease, called primary biliary cirrhosis, which can lead to transplant surgery for patients. The new study identifies 15 genetic regions that affect a person's risk of developing the disease, more than trebling the number of known genetic regions, which now stands at 22.
The study was based on the genomes of 2,500 patients with primary biliary cirrhosis and more than 7,500 apparently healthy people. The results are the first to emerge from the Wellcome Trust Case Control Consortium 3 (WTCCC3) project, a collaboration of UK scientists and clinicians, which aims to unravel the role of genetic variation in several human diseases. The findings suggest that several key immune processes underlie susceptibility to primary biliary cirrhosis (PBC).
Patients with primary biliary cirrhosis suffer irritation and swelling of the bile ducts of the liver blocking the flow of bile, which normally aids digestion. The obstruction damages liver cells and leads to scarring, known as cirrhosis. Primary biliary cirrhosis is thought to affect approximately 35 out of every 100,000 adults, but that rate almost trebles to 95 out of 100,000 in women over the age of 45. As there are no proven treatments available, the majority of patients will require a liver transplant.
The specific biological pathways underlying primary biliary cirrhosis are poorly understood although autoimmunity, where the body attacks its own cells, is known to play a significant role.
"To gain an insight into the causes of primary biliary cirrhosis we compared genetic data from patients and healthy volunteers and found 22 regions of the genome that differed significantly, 15 of which had not previously been identified," says Dr Carl Anderson, from the Wellcome Trust Sanger Institute and one of the senior authors on the paper. "By scrutinizing the genes within these regions we were able to id
|Contact: Don Powell|
Wellcome Trust Sanger Institute