# Primary focal segmental glomerulosclerosis in a patient with ankylosing spondylitis: A rare presentation requiring a broad differential in nephrotic syndrome

## TL;DR

A rare case of kidney disease called focal segmental glomerulosclerosis is reported in a patient with ankylosing spondylitis.

## Contribution

Highlights FSGS as a rare but important differential diagnosis in AS patients with nephrotic syndrome.

## Key findings

- FSGS is a rare but possible cause of kidney disease in patients with ankylosing spondylitis.
- Renal failure in AS is more commonly due to amyloidosis or IgA nephropathy.
- Clinicians should consider FSGS in the differential diagnosis for AS patients with nephrotic syndrome.

## Abstract

Ankylosing spondylitis (AS) presents with renal failure and proteinuria in a minority of cases, usually due to secondary amyloidosis or IgA nephropathy. While focal segmental glomerulosclerosis (FSGS) is less common, it should still be in the differential regardless of the patient's clinical profile.