Progressive Familial Intrahepatic Cholestasis, Type 2 (ABCB11)
Progressive familial intrahepatic cholestasis, type 2 is an autosomal recessive, pan-ethnic disorder caused by pathogenic variants in the gene ABCB11. Patients with this disease experience recurrent episodes of cholestasis, or a blockage of bile flow, starting in infancy. Excess bile salts are stored in the liver cells and leak into the bloodstream, resulting in severe itching, jaundice, and an enlarged liver. Damage of the liver cells frequently leads to liver failure and sometimes liver cancer. Many patients will require a liver transplant, usually before adulthood. Some patients with two pathogenic ABCB11 variants will develop a disease known as benign recurrent intrahepatic cholestasis, type 2. These patients have recurrent cholestasis episodes but do not develop liver failure or cancer. Patients with null variants are more likely to develop progressive rather than benign disease, but it may not be possible to predict the severity of the disease in all patients. Life expectancy may be reduced in some patients with cancer, or those requiring liver transplants that experience complications.
For information about carrier frequency and residual risk, please see the residual risk table.