A case of Lipoprotein glomerulopathy due to the pathogenic APOE Las Vegas variant c.509C>A: p. (Ala170Asp)

Abstract

This report describes a rare case of lipoprotein glomerulopathy. A 63 year-old man presented with nephrotic syndrome unresponsive to rituximab and tacrolimus. Blood tests showed a mild- to moderate hypertriglyceridemia suggesting familial dysbetalipoproteinemia (FD). Additional diagnostic procedures including lipoprotein ultracentrifugation, fast protein liquid chromatography and agarose gel electrophoresis were performed which showed increased very-low-density lipoprotein remnants corresponding to the lipid profile observed in FD patients. However, instead of the expected APOE ε2/ε2 genotype, our patient showed APOE ε3/ε4. The APOE gene was sequenced, revealing a c.509C>A:p. (Ala170Asp) variant (also known as APOE Las Vegas), which has been described once in a patient with lipoprotein glomerulopathy. Lipid-lowering therapy was initiated, which resulted in a slight improvement of renal function and lipid profile. This Dutch case confirms the pathogenicity of the APOE Las Vegas variant and emphasizes the importance of timely diagnosis of lipoprotein glomerulopathy to institute appropriate treatment.