Abstract: FR-PO621
A Case of Familial Infantile Nephrotic Syndrome Secondary to Membranous Nephropathy
Session Information
- Trainee Case Reports - IV
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1600 Pediatric Nephrology
Authors
- Rawson, Ashley E., Indiana University School of Medicine Pediatric Nephrology, Indianapolis, Indiana, United States
- Wilson, Amy C., Indiana University School of Medicine Pediatric Nephrology, Indianapolis, Indiana, United States
- Kouri, Anne, Indiana University School of Medicine Pediatric Nephrology, Indianapolis, Indiana, United States
- Khalid, Myda, Indiana University School of Medicine Pediatric Nephrology, Indianapolis, Indiana, United States
- Nailescu, Corina, Indiana University School of Medicine Pediatric Nephrology, Indianapolis, Indiana, United States
- Phillips, Carrie L., Indiana University School of Medicine, Indianapolis, Indiana, United States
- Hains, David S., Indiana University School of Medicine Pediatric Nephrology, Indianapolis, Indiana, United States
Group or Team Name
- Indiana University School of Medicine Pediatric Nephrology
Introduction
Infantile nephrotic syndrome (NS) is defined as NS onset between 3-12 months of life. It is often caused by genetic alterations of proteins involved in forming the podocyte slit diaphragm and glomerular basement membrane. Over 95% of cases are autosomal recessive and can be attributed to mutations in NPHS1, NPHS2, NPHS3, WT1, and LAMB2. Biopsy findings are usually negative for immune deposition. In very rare cases membranous nephropathy causes infantile NS; however, there are no documented cases of dominant inheritance. We describe a case of familial infantile NS with a variable histologic phenotype and atypical inheritance pattern.
Case Description
A 9-month-old male presented with 2 weeks of diffuse swelling. He had massive proteinuria with a urine protein: creatinine ratio of 22.18. His renal function, complement levels, metabolic work-up and ANA were unremarkable. Family history included a half-brother (same mother) with steroid resistant NS who presented at 1 year of age and died of sepsis at 2 years of age 8 years prior to this case. The half-brother had a kidney biopsy revealing type III membranoproliferative glomerulonephritis but genetic evaluation was not sent. Genetic evaluation on our current patient is pending; however, because of the biopsy findings of the half-brother, a biopsy was performed and consistent with membranous nephropathy. Immunofluorescence was positive for glomerular labeling of IgG (3+), IgA (2+), and C3 (4+). Additionally, glomerular capillary loops diffusely labeled with PLA2R (3+) antibody and tubular basement membranes labeled with IgG in a granular pattern. Patient currently maintains normal albumin levels on albumin infusions, furosemide, and ACE-inhibition.
Discussion
Infantile membranous nephropathy with tubular basement membrane antibodies is not currently reported in the literature. Some pediatric case reports exist but staining of the tubular basement membranes with IgG is typically in a linear pattern. The granular pattern seen in our patient is very unusual and usually seen in patients with SLE. Familial cases of these findings have not been reported. The presence of NS in half-brother suggests a dominant inheritance pattern and may suggest a novel gene mutation for infantile NS. The half-brother with a different histological pattern suggests a variable phenotype.