A 30 year old man presents with generalized edema and hypeension. Urine examination shows sub nephrotic proteinuria (< 2gm) and microscopic hematuria. Serum complement levels are decreased and he is positive for antihepatitis C antibodies. The most likely diagnosis is:

**Core Concept**
The patient's presentation of generalized edema, hypertension, subnephrotic proteinuria, microscopic hematuria, decreased serum complement levels, and positive anti-HCV antibodies suggests a renal disorder associated with hepatitis C virus (HCV) infection.

**Why the Correct Answer is Right**
The patient's symptoms and laboratory findings are consistent with membranoproliferative glomerulonephritis (MPGN), a type of glomerulonephritis characterized by the deposition of immune complexes in the glomeruli. HCV infection is a known cause of MPGN, leading to the activation of the alternative complement pathway and subsequent glomerular injury. The decreased serum complement levels and presence of anti-HCV antibodies support this diagnosis.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because IgA nephropathy typically presents with episodic hematuria and is not associated with HCV infection.
* **Option B:** This option is incorrect because minimal change disease typically presents with nephrotic syndrome (proteinuria > 3.5 gm/day) and is not associated with HCV infection.
* **Option C:** This option is incorrect because focal segmental glomerulosclerosis (FSGS) typically presents with nephrotic syndrome and is not associated with HCV infection.

**Clinical Pearl / High-Yield Fact**
HCV infection is a known cause of MPGN, and patients with HCV-related kidney disease may require antiviral therapy in addition to renal replacement therapy.

**Correct Answer:** C. Membranoproliferative glomerulonephritis (MPGN)

✓ Correct Answer: C. Membranoproliferative glomerulonephritis (MPGN)