Yorifuji-Okuno syndrome, also known as congenital hepatic fibrosis with extrahepatic biliary atresia syndrome (CHF-EBA), is an extremely rare genetic disorder characterized by the co-occurrence of congenital hepatic fibrosis (CHF) and extrahepatic biliary atresia (EBA). This syndrome was first described by Yorifuji and Okuno in 1985.
Features of Yorifuji-Okuno Syndrome:
- Congenital Hepatic Fibrosis (CHF): CHF is a condition characterized by abnormal fibrous tissue formation within the liver, leading to the development of cystic dilatations (cysts) within the bile ducts and portal areas of the liver. CHF typically presents in infancy or childhood and may lead to portal hypertension (increased blood pressure within the portal vein system), splenomegaly (enlargement of the spleen), and complications such as variceal bleeding and ascites.
- Extrahepatic Biliary Atresia (EBA): EBA is a condition characterized by the obstruction or absence of the bile ducts outside the liver, leading to impaired bile flow from the liver to the small intestine. EBA typically presents shortly after birth with jaundice (yellowing of the skin and eyes), pale stools, dark urine, and hepatomegaly (enlargement of the liver). If left untreated, EBA can lead to liver failure and death within the first few months of life.
- Hepatobiliary and Gastrointestinal Symptoms: Individuals with Yorifuji-Okuno syndrome may experience a range of hepatobiliary and gastrointestinal symptoms, including jaundice, hepatomegaly, splenomegaly, poor weight gain, failure to thrive, and signs of portal hypertension such as ascites and variceal bleeding.
- Renal and Pancreatic Anomalies: Some individuals with Yorifuji-Okuno syndrome may have associated renal (kidney) and pancreatic anomalies, such as renal cysts, renal tubular ectasia, and pancreatic ductal dilatation.
- Other Features: Additional features that may be present in individuals with Yorifuji-Okuno syndrome include intellectual disability, developmental delay, skeletal anomalies, and cardiac defects.
Genetics:
Yorifuji-Okuno syndrome is thought to have a genetic basis, although the specific genetic cause of the syndrome is not well understood. It is believed to result from mutations in genes involved in hepatic and biliary development, leading to the characteristic features of CHF and EBA.
Diagnosis:
Diagnosis of Yorifuji-Okuno syndrome is based on clinical evaluation, including assessment of the characteristic features described above, as well as imaging studies such as ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) to evaluate the liver, bile ducts, and other organs. Liver biopsy may be performed to confirm the presence of hepatic fibrosis and assess the severity of liver damage.
Treatment:
Treatment of Yorifuji-Okuno syndrome is primarily supportive and aimed at managing the symptoms and complications associated with CHF, EBA, and associated conditions. Treatment may include medical management of portal hypertension, nutritional support, management of complications such as ascites and variceal bleeding, and in some cases, surgical interventions such as liver transplantation for individuals with end-stage liver disease.
Prognosis:
The prognosis for individuals with Yorifuji-Okuno syndrome varies depending on the severity of hepatic and biliary involvement, the presence of associated complications, and the response to treatment. Early diagnosis and comprehensive management can help improve outcomes and quality of life for affected individuals. Close monitoring and multidisciplinary care are often necessary to address the complex needs of individuals with Yorifuji-Okuno syndrome.