A novel apolipoprotein E mutation, ApoE Tsukuba (Arg 114 Cys), in lipoprotein glomerulopathy

Extract

Introduction

Lipoprotein glomerulopathy (LPG) is considered a type of renal lipidosis, characterized by the presence of lipoprotein thrombi in markedly dilated capillary lumina of the affected glomeruli [1]. LPG is a rare disease; approximately 65 cases have been reported to date [2]. Patients with LPG exhibit proteinuria and progressive renal dysfunction. In most of the LPG patients, levels of intermediate-density lipoproteins are elevated, resembling type III hyperlipoproteinaemia; moreover, apolipoprotein E (ApoE) levels are also elevated. Recent genetic studies have revealed that several ApoE gene mutations are associated with LPG [3].

In this study, we report a LPG patient with a novel ApoE mutation, without plasma lipid and lipoprotein abnormalities or elevated ApoE level.

Case report

An 18-year-old Japanese female was first found to have proteinuria at an annual school health check. For the workup of her proteinuria, she was admitted to Tsukuba University Hospital. Her past history was unremarkable. She had no known family history of renal diseases or lipidosis, but her mother had splenomegaly of unknown origin since the previous year.