Focal Segmental Glomerulosclerosis (FSGS) is a serious glomerular disorder characterized by scarring that affects some (focal) segments (segmental) of the kidney’s glomeruli. It is a leading cause of nephrotic syndrome and chronic kidney disease in both adults and children and is associated with a relatively high risk of progression to end-stage kidney disease if not managed appropriately. In nephrology practice across the UAE, FSGS represents a challenging condition due to its variable causes and treatment response.

FSGS may be classified as primary, secondary, or genetic. Primary FSGS is thought to result from circulating factors that damage podocytes, the specialized cells that maintain the integrity of the glomerular filtration barrier. Secondary FSGS develops as an adaptive response to conditions such as obesity, hypertension, diabetes, reduced kidney mass, or prolonged hyperfiltration. Genetic forms are increasingly recognized and may present in younger patients or those with family history.

Damage to podocytes leads to disruption of the filtration barrier, allowing large amounts of protein to leak into the urine. Persistent proteinuria promotes inflammation and fibrosis, resulting in progressive scarring of glomeruli and gradual loss of kidney function. Unlike some other glomerular diseases, FSGS often follows an aggressive clinical course.

Patients commonly present with features of nephrotic syndrome, including swelling of the legs, face, or abdomen, frothy urine, fatigue, and weight gain due to fluid retention. Hypertension and declining kidney function are frequent as the disease advances. Laboratory findings typically show heavy proteinuria, low serum albumin, and elevated cholesterol levels.

Diagnosis requires a kidney biopsy, which demonstrates characteristic focal and segmental glomerular scarring. Additional investigations help identify secondary causes and guide management decisions. Early and accurate classification of FSGS is essential, as treatment and prognosis differ significantly between primary and secondary forms.

Management aims to reduce proteinuria, slow progression of kidney damage, and manage complications. Blood pressure control and kidney-protective strategies are essential in all patients. In primary FSGS, immunosuppressive therapy may be required to control podocyte injury. Secondary FSGS is managed by treating the underlying cause and reducing hyperfiltration stress. Long-term follow-up is critical due to the high risk of relapse and progression.
Prognosis varies, with some patients achieving remission while others progress to advanced kidney disease. Early diagnosis, individualized therapy, and sustained nephrology care significantly improve outcomes and delay kidney failure.