Focal Segmental Glomerulosclerosis

Focal Segmental Glomerulosclerosis describes a pattern of kidney damage visible under the microscope, where only some glomeruli (and only segments of those glomeruli) show scarring and dysfunction. The disease can be primary, arising from an intrinsic kidney abnormality, or secondary to systemic conditions such as HIV infection, obesity, reflux nephropathy, or certain medications. Primary FSGS is thought to result from dysfunction of podocytes, specialized cells that form the filtering barrier in the glomerulus. Recent research has identified genetic mutations in genes like NPHS2 and TRPC6 that can cause familial forms of the disease. The hallmark feature of FSGS is heavy proteinuria, with many patients losing more than 3.5 grams of protein per day in their urine. This protein loss drives many symptoms, including nephrotic syndrome characterized by edema and hypoalbuminemia. Disease progression varies widely: some patients experience remission with treatment, while others progress to end-stage renal disease. Approximately 50% of patients progress to kidney failure within 5-10 years if untreated. Early detection and aggressive management of proteinuria are critical for slowing disease progression.