A case of congenital bile acid synthesis disorder type 2 and literature review

Objective To summarize the clinical features, biochemical change and genetic mutations of a neonate with congenital bile acid synthesis disorder type 2. Methods Clinical features, blood biochemical index, gene analysis and treatment of the patient were reviewed. Results The patient presented with the symptoms of jaundice 3 days after birth but without skin itching. Pale stool was noted. Subsequently, he presented with hepatomegaly, blood coagulation disorders, left cochlear nerve damage, liver cirrhosis and remarkable growth retardation. Serum biochemistries showed that bilirubin and transaminase were elevated, while γ-GT and total bile acid was normal. Abdominal ultrasonography indicated decline of gallbladder contraction. Cholangiography showed normal extra- and intrahepatic bile ducts and patent biliary tract. Liver biopsy showed intrahepatic cholestasis. Gene testing has identified a homozygous mutation in AKR1D1 gene. Conclusion Congenital bile acid synthesis disorder should be suspected when a neonate has presented with jaundice, elevated bilirubin and transaminase, normal or reduced TBA and γ-GT. Genetic testing and urine mass spectrometry analysis can diagnose congenital bile acid synthesis disorder. Early therapy is crucial to patients with congenital bile acid synthesis disorder. Key words: Bile acid synthesis disorder; Gene; Mutation; Infant