TJP2 hepatobiliary disorders: Novel variants and clinical diversity
- PMID: 31696999
- DOI: 10.1002/humu.23947
TJP2 hepatobiliary disorders: Novel variants and clinical diversity
Abstract
To assess the spectrum of pediatric clinical phenotypes in TJP2 disease, we reviewed records of our seven patients in whom intrahepatic cholestasis was associated with biallelic TJP2 variants (13; 12 novel) and correlated clinical manifestations with mutation type. The effect of a splicing variant was analyzed with a minigene assay. The effects of three missense variants were analyzed with protein expression in vitro. Our patients had both remitting and persistent cholestasis. Three exhibited growth retardation. Six responded to treatment with cholestyramine, ursodeoxycholic acid, or both. Two had cholecystolithiasis. None required liver transplantation or developed hepatocellular or cholangiocellular malignancy. None manifested extrahepatic disease not attributable to effects of cholestasis. The variant c.2180-5T>G resulted in exon 15 skipping with in-frame deletion of 32 amino acid residues in TJP2. The three missense variants decreased but did not abolish TJP2 expression. Patients with truncating or canonical splice-site variants had clinically more severe disease. TJP2 disease in children includes a full clinical spectrum of severity, with mild or intermittent forms as well as the severe and minimal forms hitherto described. Biallelic TJP2 variants must be considered in children with clinically intermittent or resolved intrahepatic cholestasis.
Keywords: TJP2 deficiency; cholestasis; diversity; phenotypes; variants.
© 2019 Wiley Periodicals, Inc.
References
REFERENCES
-
- Adzhubei, I., Jordan, D. M., & Sunyaev, S. R. (2013). Predicting functional effect of human missense mutations using PolyPhen-2. Current Protocols in Human Genetics, 76, 7.20.1-7.20.41. https://doi.org/10.1002/0471142905.hg0720s76
-
- Baker, A., Kerkar, N., Todorova, L., Kamath, B. M., & Houwen, R. H. J. (2019). Systematic review of progressive familial intrahepatic cholestasis. Clinics and Research in Hepatology and Gastroenterology, 43(1), 20-36. https://doi.org/10.1016/j.clinre.2018.07.010
-
- Bychkov, I. O., Kamenets, E. A., Filatova, A. Y., Skoblov, M. Y., Mikhaylova, S. V., Strokova, T. V., … Zakharova, E. Y. (2019). The novel synonymous variant in LIPA gene affects splicing and causes lysosomal acid lipase deficiency. Molecular Genetics and Metabolism, 127(3), 212-215. https://doi.org/10.1016/j.ymgme.2019.06.005
-
- Carlton, V. E., Harris, B. Z., Puffenberger, E. G., Batta, A. K., Knisely, A. S., Robinson, D. L., … Bull, L. N. (2003). Complex inheritance of familial hypercholanemia with associated mutations in TJP2 and BAAT. Nature Genetics, 34(1), 91-96. https://doi.org/10.1038/ng1147
-
- Davit-Spraul, A., Gonzales, E., Baussan, C., & Jacquemin, E. (2010). The spectrum of liver diseases related to ABCB4 gene mutations: Pathophysiology and clinical aspects. Seminars in Liver Disease, 30(2), 134-146. https://doi.org/10.1055/s-0030-1253223
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