A 48-year-old Caucasian man, diagnosed with diabetes 5 years ago, comes to the physician because of palpitations, Physical examination shows a diffuse darkening of his skin and testicular atrophy. Laboratory studies show elevated liver function and elevated blood sugars. A liver biopsy shows significantly elevated iron levels A diagnosis of hereditary hemochromatosis is made. Which one of the following laboratory findings is seen in hereditary hemochromatosis?

**Core Concept**
Hereditary hemochromatosis is a genetic disorder characterized by excessive iron accumulation in the body, leading to tissue damage and organ dysfunction. The condition is caused by mutations in the HFE gene, which regulates iron absorption in the intestine.

**Why the Correct Answer is Right**
In hereditary hemochromatosis, the increased iron absorption leads to elevated serum iron levels, which in turn cause liver damage, skin pigmentation changes, and endocrine dysfunction. The liver biopsy finding of significantly elevated iron levels is a hallmark of the disease. The elevated iron levels can also lead to the formation of free radicals, which damage the liver and other organs.

**Why Each Wrong Option is Incorrect**
**Option A:** Elevated serum ferritin levels are indeed seen in hereditary hemochromatosis, but this option is not the most specific finding.

**Option B:** Elevated liver enzymes are seen in hereditary hemochromatosis due to liver damage, but this is not a specific laboratory finding for the disease.

**Option C:** Elevated blood sugars are seen in hereditary hemochromatosis due to pancreatic damage, but this is not a specific laboratory finding for the disease.

**Clinical Pearl / High-Yield Fact**
Hereditary hemochromatosis can be screened for using genetic testing for the HFE gene mutation. Early diagnosis and phlebotomy treatment can prevent organ damage and improve outcomes.

**Correct Answer:** Elevated serum transferrin saturation (or elevated serum iron levels) is seen in hereditary hemochromatosis.

✓ Correct Answer: D. Decreased total iron-binding capacity