BACKGROUND Functioning farnesoid X receptor(FXR;encoded by NR1H4)is key to normal bile acid homeostasis.Biallelic mutations in NR1H4 are reported in a few children with intrahepatic cholestasis.We describe a boy with ...BACKGROUND Functioning farnesoid X receptor(FXR;encoded by NR1H4)is key to normal bile acid homeostasis.Biallelic mutations in NR1H4 are reported in a few children with intrahepatic cholestasis.We describe a boy with progressive familial intrahepatic cholestasis and homozygous mutation in NR1H4.CASE SUMMARY A boy had severe neonatal cholestasis with moderate hypercholanemia and persistently elevated alpha-fetoprotein.Despite medical treatment,coagulopathy was uncontrollable,prompting liver transplantation at age 8 mo with incidental splenectomy.The patient experienced catch-up growth with good liver function and did not develop allograft steatosis.However,1 year after transplant,he died from an acute infection,considered secondary to immunosuppression and asplenia.A homozygous protein-truncating mutation,c.547C>T,p.(Arg183Ter),was subsequently identified in NR1H4,and both parents were shown to be heterozygous carriers.Absence of FXR and of bile salt export pump expression was confirmed by immunostaining of explanted liver.CONCLUSION Severe cholestasis with persistently high alpha-fetoprotein and modest elevation of serum bile acid levels may suggest FXR deficiency.Some patients with FXR deficiency may not develop allograft steatosis and may respond well to liver transplantation.展开更多
基金National Institutes of Health,No.R01DK094828and National Human Genome Research Institute,No.UM1 HG006493 and No.U24 HG008956.
文摘BACKGROUND Functioning farnesoid X receptor(FXR;encoded by NR1H4)is key to normal bile acid homeostasis.Biallelic mutations in NR1H4 are reported in a few children with intrahepatic cholestasis.We describe a boy with progressive familial intrahepatic cholestasis and homozygous mutation in NR1H4.CASE SUMMARY A boy had severe neonatal cholestasis with moderate hypercholanemia and persistently elevated alpha-fetoprotein.Despite medical treatment,coagulopathy was uncontrollable,prompting liver transplantation at age 8 mo with incidental splenectomy.The patient experienced catch-up growth with good liver function and did not develop allograft steatosis.However,1 year after transplant,he died from an acute infection,considered secondary to immunosuppression and asplenia.A homozygous protein-truncating mutation,c.547C>T,p.(Arg183Ter),was subsequently identified in NR1H4,and both parents were shown to be heterozygous carriers.Absence of FXR and of bile salt export pump expression was confirmed by immunostaining of explanted liver.CONCLUSION Severe cholestasis with persistently high alpha-fetoprotein and modest elevation of serum bile acid levels may suggest FXR deficiency.Some patients with FXR deficiency may not develop allograft steatosis and may respond well to liver transplantation.
