Falcão D, Pedroto I, Moreira T. The wide phenotypic and genetic spectrum of ABCB4 gene deficiency: A case series.
Dig Liver Dis 2022;
54:221-227. [PMID:
34376370 DOI:
10.1016/j.dld.2021.07.003]
[Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND
ABCB4-gene mutations are responsible for several cholestatic diseases with a heterogeneous clinical spectrum.
AIMS
To analyse phenotype/genotype relationships in ABCB4-mutations.
METHODS
Retrospective characterization of adult patients with ABCB4-variations diagnosed between 2015 and 2020. Genotype-phenotype correlations were analysed and compared with previously reported data.
RESULTS
Twenty patients from 12 families were included. Thirteen patients presented recurrent elevated liver tests, eight fulfilled Low-Phospholipid-Associated-Cholelithiasis syndrome criteria, five had Intrahepatic Cholestasis of Pregnancy and three patients developed Drug-Induced-Liver-Injury. ABCB4 screening identified eight different mutations. Five patients were homozygotes to the variant c.504T > C. Ten patients had one mutation in heterozygote-state and five patients had two mutations in compound-heterozygosity. Portal fibrosis occurred in two patients. One of these patients presented progressive fibrosis and progression of cholestasis despite ursodeoxycholic-acid treatment, this patient also harbours a ABCB11 polymorphism.
CONCLUSION
Although, phenotype-genotype relationships have not been clearly defined, an early diagnosis of ABCB4-variants may have an important role in management decisions and patient outcomes. To our knowledge, we describe a not previously reported deletion (c.1181delT) in ABCB4. The c.504T > C polymorphism, although a silent mutation at the protein level, seems to be associated to different cholestatic diseases. The role of other genes variants, namely ABCB11, as co-factor for progression, needs to be clarified.
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