PFIC is a group of rare inherited disorders that cause a digestive fluid called bile to build up in the liver (pictured above in orange), causing significant damage that often requires a transplant. (Image credit: SEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY via Getty Images)
Disease name: Progressive familial intrahepatic cholestasis (PFIC)
Affected populations: PFIC is a set of rare genetic disorders that cause progressive liver failure. The exact prevalence of PFIC is unknown, but estimates indicate that the disorders affect between 1 in 100,000 and 1 in 50,000 people worldwide. In the United States, fewer than 50,000 people are estimated to have PFIC.
Causes: Patients with PFIC have genetic mutations that affect the liver's ability to secrete a digestive fluid known as bile into the digestive tract.
Bile is a yellowish-green fluid produced by the liver. It normally flows into the digestive tract, helping to break down fats, absorb vitamins from food, and eliminate waste through stool.
However, in patients with PFH, bile accumulates in the liver, causing damage to the organ. As liver cells die, they are replaced by scar tissue, a process called fibrosis.
There are three types of PFH – PFH1, PFH2 and PFH3 – which are distinguished by mutations in different genes that code for proteins needed for normal liver function. PFH is inherited in an autosomal recessive manner, meaning that children must inherit two copies of the corresponding mutated gene – one from each parent – to develop the disease.
PFIC leads to severe scarring of the liver, known as cirrhosis.
Symptoms: All patients with PFH develop liver symptoms, which usually begin in infancy. These include severe itching; yellowing of the skin and whites of the eyes, known as jaundice; growth retardation; and high blood pressure in the vein that carries blood from the digestive system to the liver. The itching is caused by excess bile acids, which irritate nerve cells in the body.
Patients with PFS1 may also experience additional symptoms such as short stature, deafness, diarrhea, and inflammation of the pancreas. And those with PFS2 are at increased risk of developing hepatocellular carcinoma, a type of liver cancer.
Symptoms of liver failure usually appear before adulthood in patients with PSV.
Sourse: www.livescience.com
