AUTHOR=Cao Wenya , Guo Xiaoli , Zhao Xue , Gao Yi TITLE=Case report: A rare case of IgA nephropathy associated with type II Abernethy malformation JOURNAL=Frontiers in Medicine VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1659665 DOI=10.3389/fmed.2025.1659665 ISSN=2296-858X ABSTRACT=Abernethy malformation is a rare congenital vascular anomaly involving extrahepatic portosystemic shunting, with only a handful of reported cases coexisting with IgA nephropathy. We present a case of a patient who initially manifested with proteinuria and hematuria, and later developed hepatic encephalopathy, prompting vascular imaging that identified a type II Abernethy malformation characterized by an extrahepatic portocaval shunt. A diagnosis of type II Abernethy malformation was established. The patient underwent laparoscopic partial shunt disconnection, which led to a marked reduction in proteinuria (from 0.8–2.1 g/d to 0.19–0.29 g/d). This case, along with previous reports, suggests that portosystemic shunting in Abernethy malformation may be a pathogenic factor in IgA nephropathy. Surgical correction of the shunt may confer renal benefits in selected cases and deserves further investigation.