ABCB11 Gene
ATP binding cassette subfamily B member 11
ALIAS SYMBOLS
ABC16
SPGP
PFIC-2
PGY4
Your Results
Sign InDescription
The ABCB11 gene provides instructions for making a protein called the bile salt export pump (BSEP), which is found in the liver. Bile salts are a component of bile, which is used to digest fats. Bile salts are produced by liver cells and then transported out of the cell by BSEP to make bile. The release of bile salts from liver cells is critical for the normal secretion of bile.
CHROMOSOME
2
LOCATION
q31.1
LOCUS TYPE
gene with protein product
VARIANTS
743
Phenotypes
Progressive familial intrahepatic cholestasis type 2
Progressive familial intrahepatic cholestasis (PFIC) is a disorder that causes progressive liver disease, which typically leads to liver failure. In people with PFIC, liver cells are less able to secrete a digestive fluid called bile. The buildup of bile in liver cells causes liver disease in affected individuals.
Signs and symptoms of PFIC typically begin in infancy and are related to bile buildup and liver disease. Specifically, affected individuals experience severe itching, yellowing of the skin and whites of the eyes (jaundice), failure to gain weight and grow at the expected rate (failure to thrive), high blood pressure in the vein that supplies blood to the liver (portal hypertension), and an enlarged liver and spleen (hepatosplenomegaly).
There are three known types of PFIC: PFIC1, PFIC2, and PFIC3. The types are also sometimes described as shortages of particular proteins needed for normal liver function. Each type has a different genetic cause.
In addition to signs and symptoms related to liver disease, people with PFIC1 may have short stature, deafness, diarrhea, inflammation of the pancreas (pancreatitis), and low levels of fat-soluble vitamins (vitamins A, D, E, and K) in the blood. Affected individuals typically develop liver failure before adulthood.
The signs and symptoms of PFIC2 are typically related to liver disease only; however, these signs and symptoms tend to be more severe than those experienced by people with PFIC1. People with PFIC2 often develop liver failure within the first few years of life. Additionally, affected individuals are at increased risk of developing a type of liver cancer called hepatocellular carcinoma.
Most people with PFIC3 have signs and symptoms related to liver disease only. Signs and symptoms of PFIC3 usually do not appear until later in infancy or early childhood; rarely, people are diagnosed in early adulthood. Liver failure can occur in childhood or adulthood in people with PFIC3.
Benign recurrent intrahepatic cholestasis type 2
Benign recurrent intrahepatic cholestasis (BRIC) is characterized by episodes of liver dysfunction called cholestasis. During these episodes, the liver cells have a reduced ability to release a digestive fluid called bile. Because the problems with bile release occur within the liver (intrahepatic), the condition is described as intrahepatic cholestasis. Episodes of cholestasis can last from weeks to months, and the time between episodes, during which there are usually no symptoms, can vary from weeks to years.
The first episode of cholestasis usually occurs in an affected person's teens or twenties. An attack typically begins with severe itchiness (pruritus), followed by yellowing of the skin and whites of the eyes (jaundice) a few weeks later. Other general signs and symptoms that occur during these episodes include a vague feeling of discomfort (malaise), irritability, nausea, vomiting, and a lack of appetite. A common feature of BRIC is the reduced absorption of fat in the body, which leads to excess fat in the feces (steatorrhea). Because of a lack of fat absorption and loss of appetite, affected individuals often lose weight during episodes of cholestasis.
BRIC is divided into two types, BRIC1 and BRIC2, based on the genetic cause of the condition. The signs and symptoms are the same in both types.
This condition is called benign because it does not cause lasting damage to the liver. However, episodes of liver dysfunction occasionally develop into a more severe, permanent form of liver disease known as progressive familial intrahepatic cholestasis (PFIC). BRIC and PFIC are sometimes considered to be part of a spectrum of intrahepatic cholestasis disorders of varying severity.
Progressive familial intrahepatic cholestasis type 3
Progressive familial intrahepatic cholestasis (PFIC) is a disorder that causes progressive liver disease, which typically leads to liver failure. In people with PFIC, liver cells are less able to secrete a digestive fluid called bile. The buildup of bile in liver cells causes liver disease in affected individuals.
Signs and symptoms of PFIC typically begin in infancy and are related to bile buildup and liver disease. Specifically, affected individuals experience severe itching, yellowing of the skin and whites of the eyes (jaundice), failure to gain weight and grow at the expected rate (failure to thrive), high blood pressure in the vein that supplies blood to the liver (portal hypertension), and an enlarged liver and spleen (hepatosplenomegaly).
There are three known types of PFIC: PFIC1, PFIC2, and PFIC3. The types are also sometimes described as shortages of particular proteins needed for normal liver function. Each type has a different genetic cause.
In addition to signs and symptoms related to liver disease, people with PFIC1 may have short stature, deafness, diarrhea, inflammation of the pancreas (pancreatitis), and low levels of fat-soluble vitamins (vitamins A, D, E, and K) in the blood. Affected individuals typically develop liver failure before adulthood.
The signs and symptoms of PFIC2 are typically related to liver disease only; however, these signs and symptoms tend to be more severe than those experienced by people with PFIC1. People with PFIC2 often develop liver failure within the first few years of life. Additionally, affected individuals are at increased risk of developing a type of liver cancer called hepatocellular carcinoma.
Most people with PFIC3 have signs and symptoms related to liver disease only. Signs and symptoms of PFIC3 usually do not appear until later in infancy or early childhood; rarely, people are diagnosed in early adulthood. Liver failure can occur in childhood or adulthood in people with PFIC3.
External Links
HGNC
Ensembl
NCBI
OMIM