Progressive familial intrahepatic cholestasis （PFIC） type 2 is caused by mutations in ABCB11, which encodes bile salt export pump （BSEP）. We report a Thai female infant who presented with progressive cholestatic j...Progressive familial intrahepatic cholestasis （PFIC） type 2 is caused by mutations in ABCB11, which encodes bile salt export pump （BSEP）. We report a Thai female infant who presented with progressive cholestatic jaundice since 1 mo of age, with normal serum y-glutamyltransferase. Immunohistochemical staining of the liver did not demonstrate BSEP along the canaliculi, while multidrug resistance protein 3 was expressed adequately. Novel mutations in ABCB11, a four-nucleotide deletion in exon 3, c.90_93delGAAA, and a single-nucleotide insertion in exon 5, c.249_250insT, were identified, with confirmation in her parents. These mutations were predicted to lead to synthesis of truncated forms of BSEP. Immunostaining and mutation analysis thus established the diagnosis of PFIC type展开更多
AIM: To investigate clinical profiles and mutations of ABCB11 in Koreans with progressive familial intrahepatic cholestasis 2 and review the differences between Koreans and others.METHODS: Of 47 patients with neonatal...AIM: To investigate clinical profiles and mutations of ABCB11 in Koreans with progressive familial intrahepatic cholestasis 2 and review the differences between Koreans and others.METHODS: Of 47 patients with neonatal cholestasis, five infants had chronic intrahepatic cholestasis with normal γ-glutamyl transpeptidase. Direct sequencing analyses of ABCB11, including exons and introns, were performed from peripheral blood.RESULTS: Living donor-liver transplantation was performed in four patients because of rapidly progressive hepatic failure and hepatocellular carcinoma. Three missense mutations were found in two patients: compound heterozygous 677C>T(S226L)/3007G>A(G1003R) and heterozygous 2296G>A(G766R). The mutations were located near and in the transmembranous space. CONCLUSION: Alterations in the transmembrane of the bile salt export pump in the Korean infants were different from those previously reported in Chinese, Japanease, Taiwan Residents, and European patients.展开更多
Background/Aims: Inherited dysfunction of the bile salt export pump BSEP (ABCB11) causes a progressive and a benign form of familial intrahepatic cholestasis, denominated as PFIC2 and BRIC2, respectively. We functiona...Background/Aims: Inherited dysfunction of the bile salt export pump BSEP (ABCB11) causes a progressive and a benign form of familial intrahepatic cholestasis, denominated as PFIC2 and BRIC2, respectively. We functionally characterized novel ABCB11 mutations encountered in two patients with a PFIC2 and a BRIC2 phenotype, respectively. Methods: BSEP expression was determined in liver biopsies by immunohistochemistry. ABCB11 mutations were functionally characterized by taurocholate transport in SF9 cells transfected with human ABCB11. Results: The PFIC2 patient was compound heterozygous for a splicingmutation in intron 4 ((+ 3)A >C) combined with an early stop codon at position 930 (R930X), while the BRIC2 patient was compound heterozygous for two nonsynonymous mutations in exon 9 (E297G) and exon 12 (R432T), respectively. Hepatic BSEP expression was absent in PFIC2 and preserved in BRIC2. In BRIC2, taurocholate transport was decreased to 13% and 20% of reference levels for R432T and E297G, respectively. Conclusions: The intron 4 (+ 3)A >C, R930X and R432T represent previously undescribed mutations of the ABCB11 gene that confer a PFIC2 and a BRIC2 phenotype, respectively. By combining functional in-vitro characterization with immunohistochemical detection of variant BSEP we provide direct evidence for the role of ABCB11 mutations in the pathogenesis of different forms of intrahepatic cholestasis.展开更多
Introduction The ABCB11 gene encodes for the bile salt export pump(BSEP)-the main exporter of bile acids expressed on the canalicular membrane of the hepatocyte[1-3].Pathogenic variants in the ABCB11 gene can lead to ...Introduction The ABCB11 gene encodes for the bile salt export pump(BSEP)-the main exporter of bile acids expressed on the canalicular membrane of the hepatocyte[1-3].Pathogenic variants in the ABCB11 gene can lead to a range of clinical conditions.These conditions vary from benign recurrent intrahepatic cholestasis type 2(BRIC2),which is a non-severe disorder characterized by occasional episodes of low levels of gamma-glutamyl transferase(GGT)cholestasis,to progressive familial intrahepatic cholestasis type 2(PFIC2),which is more severe and may necessitate liver transplantation.Recently,odevixibat-an inhibitor of the ileal bile acid transporter-was able to reduce itching and serum bile acid concentrations in a randomized-controlled study,including patients with PFIC2.Odevixibat provide treatment benefits in a disease with high unmet medical needs[4].展开更多
文摘Progressive familial intrahepatic cholestasis （PFIC） type 2 is caused by mutations in ABCB11, which encodes bile salt export pump （BSEP）. We report a Thai female infant who presented with progressive cholestatic jaundice since 1 mo of age, with normal serum y-glutamyltransferase. Immunohistochemical staining of the liver did not demonstrate BSEP along the canaliculi, while multidrug resistance protein 3 was expressed adequately. Novel mutations in ABCB11, a four-nucleotide deletion in exon 3, c.90_93delGAAA, and a single-nucleotide insertion in exon 5, c.249_250insT, were identified, with confirmation in her parents. These mutations were predicted to lead to synthesis of truncated forms of BSEP. Immunostaining and mutation analysis thus established the diagnosis of PFIC type
文摘AIM: To investigate clinical profiles and mutations of ABCB11 in Koreans with progressive familial intrahepatic cholestasis 2 and review the differences between Koreans and others.METHODS: Of 47 patients with neonatal cholestasis, five infants had chronic intrahepatic cholestasis with normal γ-glutamyl transpeptidase. Direct sequencing analyses of ABCB11, including exons and introns, were performed from peripheral blood.RESULTS: Living donor-liver transplantation was performed in four patients because of rapidly progressive hepatic failure and hepatocellular carcinoma. Three missense mutations were found in two patients: compound heterozygous 677C>T(S226L)/3007G>A(G1003R) and heterozygous 2296G>A(G766R). The mutations were located near and in the transmembranous space. CONCLUSION: Alterations in the transmembrane of the bile salt export pump in the Korean infants were different from those previously reported in Chinese, Japanease, Taiwan Residents, and European patients.
文摘Background/Aims: Inherited dysfunction of the bile salt export pump BSEP (ABCB11) causes a progressive and a benign form of familial intrahepatic cholestasis, denominated as PFIC2 and BRIC2, respectively. We functionally characterized novel ABCB11 mutations encountered in two patients with a PFIC2 and a BRIC2 phenotype, respectively. Methods: BSEP expression was determined in liver biopsies by immunohistochemistry. ABCB11 mutations were functionally characterized by taurocholate transport in SF9 cells transfected with human ABCB11. Results: The PFIC2 patient was compound heterozygous for a splicingmutation in intron 4 ((+ 3)A >C) combined with an early stop codon at position 930 (R930X), while the BRIC2 patient was compound heterozygous for two nonsynonymous mutations in exon 9 (E297G) and exon 12 (R432T), respectively. Hepatic BSEP expression was absent in PFIC2 and preserved in BRIC2. In BRIC2, taurocholate transport was decreased to 13% and 20% of reference levels for R432T and E297G, respectively. Conclusions: The intron 4 (+ 3)A >C, R930X and R432T represent previously undescribed mutations of the ABCB11 gene that confer a PFIC2 and a BRIC2 phenotype, respectively. By combining functional in-vitro characterization with immunohistochemical detection of variant BSEP we provide direct evidence for the role of ABCB11 mutations in the pathogenesis of different forms of intrahepatic cholestasis.
基金Thanks to Fondazione Roma for the invaluable support for scientific research(FR-CEMAD 21-25).
文摘Introduction The ABCB11 gene encodes for the bile salt export pump(BSEP)-the main exporter of bile acids expressed on the canalicular membrane of the hepatocyte[1-3].Pathogenic variants in the ABCB11 gene can lead to a range of clinical conditions.These conditions vary from benign recurrent intrahepatic cholestasis type 2(BRIC2),which is a non-severe disorder characterized by occasional episodes of low levels of gamma-glutamyl transferase(GGT)cholestasis,to progressive familial intrahepatic cholestasis type 2(PFIC2),which is more severe and may necessitate liver transplantation.Recently,odevixibat-an inhibitor of the ileal bile acid transporter-was able to reduce itching and serum bile acid concentrations in a randomized-controlled study,including patients with PFIC2.Odevixibat provide treatment benefits in a disease with high unmet medical needs[4].
