A Novel Homozygous USP53 Splicing Variant Disrupting the Gene Function that Causes Cholestasis Phenotype and Review of the Literature [post]

ALPER GEZDIRICI, ÖZLEM KALAYCIK ŞENGÜL, MUSTAFA DOĞAN, BANU YILMAZ ÖZGÜVEN, EKREM AKBULUT
2021 unpublished
Background: Hereditary cholestasis is a heterogeneous group of liver diseases that mostly show autosomal recessive inheritance. The phenotype of cholestasis is highly variable. Molecular genetic testing offers a useful approach to differentiate different types of cholestasis because some symptoms and findings overlap. Biallelic variants in USP53 have recently been reported in cholestasis phenotype. In this study we aim to characterize clinical findings and biological insights on a novel USP53
more » ... lice variant causing cholestasis phenotype and review of the literature. Methods and Results: We reported a novel splice variant (NM_019050.2:c.238-1G>C) in the USP53 gene via whole exome sequencing in a patient with cholestasis phenotype. This variant was confirmed by sanger sequencing and as a result of family segregation analysis; it was found to be a heterozygous state in the parents and the other healthy elder brother of our patient. According to in-silico analyses; the change in the splice region resulted in an increase in the length of exon 1, whereas the stop codon after the additional 3 amino acids (VTF) caused the protein to terminate prematurely. Thus, the mature USP53 protein, consisting of 1.073 amino acids, has been reduced to a small protein of 82 amino acids.Conclusions: We propose a model for the tertiary structure of USP53 for the first time, together with all these data, we support the association of biallelic variants of the USP53 gene with the cholestasis phenotype. We also presented a comparison of previously reported patients with the USP53-associated cholestasis phenotype to contribute to the literature.
doi:10.21203/rs.3.rs-762230/v1 fatcat:7cchn5aubjbuvlukg7dc7lchuy