Diagnosis and treatment of an inborn error of bile acid synthesis type 4: A case report

BACKGROUND: Inborn error of bile acid synthesis type 4 is a peroxisomal disease with impaired bile acid synthesis caused by a-methylacyl-CoA racemase (AMACR) gene mutation. The disease is usually found in children with mild to severe liver disease, cholestasis and poor fat-soluble vitamin absorption. At present, there is no report of inborn errors of bile acid synthesis type 4 in adults with liver disease and poor fat-soluble vitamin absorption. CASE SUMMARY: A 71-year-old man was hospitalized in our department for recurrent liver dysfunction. The clinical manifestations were chronic liver disease and yellow skin and sclera. Serum transaminase, bilirubin and bile acid were abnormally increased; and fat-soluble vitamins decreased. Liver cirrhosis and ascites were diagnosed by computed tomography. The patient had poor coagulation function and ascites and did not undergo liver puncture. Genetic testing showed AMACR gene missense mutation. The patient was diagnosed with inborn error of bile acid synthesis type 4. He was treated with ursodeoxycholic acid, liver protection and vitamin supplementation, and jaundice of the skin and sclera was reduced. The indicators of liver function and the quality of life were significantly improved. CONCLUSION: When adults have recurrent liver function abnormalities, physicians should be alert to genetic diseases and provide timely treatment.