Kidney Week

Abstract: FR-PO0135

Primary FSGS in a Patient Who Is a Carrier of Bardet-Biedl Syndrome

Session Information

• Hereditary Glomerular and Tubulointerstitial Kidney Diseases
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Genetic Diseases of the Kidneys

• 1202 Genetic Diseases of the Kidneys: Non-Cystic (Complex and Non-Cystic Monogenic)

Authors

• Kae, Soo Hyun, Hospital of Central Connecticut at New Britain, New Britain, Connecticut, United States

Soo Hyun Kae, DO

• Dyquiangco, Rachelle V., Starling Nephrology, New Britain, Connecticut, United States

Rachelle V. Dyquiangco, MD

• Niranjan, Sankar Narayan, Stanford University School of Medicine, Stanford, California, United States

Sankar Narayan Niranjan, MD, FASN

Introduction

Bardet-Biedl Syndrome (BBS) is a rare autosomal recessive genetic disorder that affects approximately 1 in 250,000 people around the world¹. The hallmark of the disorder is mutations leading to defective cilia, causing vision loss due to cone-rod dystrophy, renal malformations, learning difficulties, obesity, polydactyly, and hypogonadism². Renal manifestations include cystic tubular disease, dysplastic renal disease, and FSGS due to concentrating defects³. Secondary renal disease may occur later in life from hypertension and diabetes, which are frequently observed in people with BBS due to their predisposition to obesity. Setmelanotide, a melanocortin receptor agonist, was FDA-approved in 2022 for the treatment of obesity and control of hunger in patients with BBS⁴.

Case Description

43yoF with history of ‘nephrotic syndrome’ diagnosed at 3 years of age in her home country treated with steroids until her mid-teens, normal baseline renal function with baseline creatinine (Cr) of 0.79 mg/dL, and developmental delay who presented with bilateral lower extremity edema and was found to have nephrotic syndrome with acute kidney injury (AKI) with Cr peaking at 2.05 mg/dL, proteinuria of estimated 38 g/day per protein/creatinine ratio, and hypoalbuminemia of 1.6 g/dL. She underwent renal biopsy, which showed findings consistent with primary focal segmental and global glomerulosclerosis (FSGS) with electron microscopy showing 100% foot effacement. She had genetic testing done, which did not show any pathogenic genes, but did test positive as a carrier for Bardet-Biedl Syndrome (BBS). She was discharged on high-dose prednisone, and later, tacrolimus was added during outpatient follow-up with improvement in her renal function with last Cr of 1.12 mg/dL, edema, and proteinuria.

Discussion

Development of chronic kidney disease (CKD) from renal manifestations remains the main driver of morbidity and mortality in BBS³. Early diagnosis, if there are any known carriers in the family, remains key to early detection and subsequent management of renal disease and other major clinical manifestations of BBS. We hope this case report helps raise awareness of BBS to the nephrology community.