A 28-year-old man has lenticonus and ESRD. His maternal uncle also died of similar illness. What is the diagnosis?
## **Core Concept**
The question describes a patient with lenticonus and end-stage renal disease (ESRD), along with a family history of a similar illness. This combination of symptoms suggests a hereditary condition affecting both the kidneys and the eyes. The key here is to identify a disorder that can cause both renal failure and specific ocular abnormalities.
## **Why the Correct Answer is Right**
The correct answer, **Alport syndrome**, is a genetic disorder characterized by kidney disease, hearing loss, and eye abnormalities. It is caused by mutations in the genes that encode for type IV collagen, a crucial component of the basement membranes in the kidneys, ears, and eyes. The condition leads to progressive kidney disease, often resulting in ESRD, and is associated with ocular features such as anterior lenticonus, which is a conical protrusion of the lens. The family history, particularly the involvement of a maternal uncle, hints at an X-linked inheritance pattern, which is common for Alport syndrome.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, other choices might include conditions like diabetic nephropathy, which does not usually present with lenticonus or a strong familial component in this pattern.
- **Option B:** Similarly, this option is not specified, but another condition might be a systemic vasculitis, which can cause renal failure but does not typically cause lenticonus or such a clear familial pattern.
- **Option C:** Without specifics, it's hard to address, but conditions like Fabry disease could be considered; it causes renal failure and involves the eyes but is less commonly associated with the specific pattern of inheritance and lenticonus.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that Alport syndrome is a classic cause of ESRD with a familial component and is associated with specific ocular abnormalities like anterior lenticonus. The condition often presents with hematuria and proteinuria, progressing to ESRD. The X-linked form, the most common, primarily affects males, while females are usually carriers but can be affected to a lesser degree.
## **Correct Answer: D. Alport syndrome**