A 20-year-old male is presented with end stage renal failure. Since 13 years of age, he has had progressive renal insufficiency initially with episodes of painless haematuria. He also has progressive deafness. His brother suffers from similar illness. What is the most likely diagnosis –

**Core Concept**
Alport syndrome is a genetic disorder characterized by progressive renal insufficiency, hearing loss, and ocular abnormalities. It is caused by mutations in the COL4A3, COL4A4, or COL4A5 genes, which encode for type IV collagen, a critical component of the glomerular basement membrane.

**Why the Correct Answer is Right**
The patient's symptoms of progressive renal insufficiency and hearing loss, along with the family history of a similar illness, are consistent with Alport syndrome. The condition is inherited in an X-linked pattern, meaning the gene responsible for the condition is located on the X chromosome. Males, who have only one X chromosome, are more likely to express the condition, while females, who have two X chromosomes, may be carriers or have a milder form of the disease. The presence of type IV collagen mutations leads to the degradation of the glomerular basement membrane, resulting in renal failure.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Alport syndrome is a genetic disorder, not a result of a post-infectious or autoimmune process.

**Option B:** This option is incorrect because Alport syndrome is characterized by progressive renal insufficiency and hearing loss, not by episodes of severe hypertension.

**Option C:** This option is incorrect because Alport syndrome is a genetic disorder, not a result of a toxic or metabolic cause.

**Clinical Pearl / High-Yield Fact**
Alport syndrome is an X-linked genetic disorder, making it more likely to affect males. The condition is characterized by the presence of red blood cell casts in the urine, which can be a diagnostic clue.

**Correct Answer:** C. Alport syndrome.

✓ Correct Answer: A. Alpo syndrome