Progressive Familial Intrahepatic Cholestasis (PFIC), also known as "Byler's Disease," is a rare genetic disorder in which children are unable to properly excrete bile fluid from the liver. Accumulation of toxic bile fluid in the liver leads to progressive damage over time. Additionally, the absence of bile fluid affects fat absorption and can result in nutritional deficiencies. There are three types of progressive familial intrahepatic cholestasis, each resulting from disorders in three different proteins involved in bile salt transport in the liver.
Symptoms of the disorder are usually observed during the first few months of life, although some children may lead normal lives until their second decade. In many cases, PFIC can rapidly progress to cirrhosis and liver failure, possibly requiring liver transplantation. PFIC can manifest as itching, jaundice, growth failure, malnutrition, or complications due to poor fat-soluble vitamin absorption. One form of PFIC might result in gallstones, although this is an extremely rare cause of gallstones in children.
Blood tests are used to measure liver function. If there is suspicion of PFIC, specialized blood tests can be ordered to measure specific markers such as bile acids, and genetic testing may be performed in some cases. A liver biopsy is required for diagnosis, and special staining methods can confirm the diagnosis.
The treatment of advanced progressive familial intrahepatic cholestasis involves medications to manage symptoms, particularly itching, and providing nutritional supplements to address impaired fat absorption and some vitamin deficiencies. Certain surgical methods can be used to reduce the amount of bile fluid accumulating in the liver, aiming to slow disease progression and alleviate symptoms. This procedure is known as Partial External Biliary Diversion (PEBD).
Recently, medication has been approved by the American regulatory authorities for PFIC, which treats itching and prevents disease progression. Clinical trials for this medication were conducted successfully. For patients who progress to liver failure despite maximum medical therapy, liver transplantation is an option.