Mutations in TJP2 cause progressive cholestatic liver disease

Abstract
Richard Thompson, Melissa Sambrotta and colleagues show that biallelic mutations in TJP2 cause severe cholestatic liver disease. Their findings suggest that loss of TJP2 protein disrupts the structural integrity of tight junctions in liver tissue, resulting in progressive liver damage. Elucidating genetic causes of cholestasis has proved to be important in understanding the physiology and pathophysiology of the liver. Here we show that protein-truncating mutations in the tight junction protein 2 gene (TJP2) cause failure of protein localization and disruption of tight-junction structure, leading to severe cholestatic liver disease. These findings contrast with those in the embryonic-lethal knockout mouse, highlighting differences in redundancy in junctional complexes between organs and species.