Hemochromatosis

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Hemochromatosis

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USMLE® Step 1 style questions USMLE

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A 45-year-old man comes to his primary care provider for evaluation of fatigue, which began six months ago. He has felt more tired than usual and has had decreased libido over the same time period. The patient attributes these symptoms to recent stress at work as an attorney. Past medical history is noncontributory and he does not drink alcohol or smoke cigarettes. Temperature is 36.5°C (97.7°F), pulse is 60/min, respirations are 14/min, and blood pressure is 130/82 mm Hg. Physical examination shows diffuse hyperpigmentation of the skin. The liver is palpated 4 cm below the right costal margin. Mild testicular atrophy is noted. Laboratory testing reveals the following results:  



If untreated, this patient’s condition would most likely give rise to which of the following liver findings?  

External References

First Aid

2024

2023

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Arthropathy

hemochromatosis p. 402

Autosomal recessive disorders

hemochromatosis p. 402

Chelation

hemochromatosis p. 402

Chromosome abnormalities

hemochromatosis p. 402

Cirrhosis p. 396

hemochromatosis p. 402

Deferasirox

hemochromatosis p. 402

Deferiprone

hemochromatosis p. 402

Deferoxamine

hemochromatosis p. 402

Diabetes mellitus p. 350-358

hemochromatosis p. 402

Dilated cardiomyopathy p. 315, 316, 477

hemochromatosis p. 402

Hemochromatosis p. 402

calcium pyrophosphate deposition disease p. 473

cardiomyopathy with p. 315

chromosome association p. 62

free radical injury p. 211

hepatocellular carcinoma and p. 399

HLA-A3 and p. 98

Hepatocellular carcinomas p. 399

hemochromatosis p. 402

HFE gene

hemochromatosis and p. 402

Hyperpigmentation

hemochromatosis p. 402

Hypogonadism

hemochromatosis p. 402

Iron

in hemochromatosis p. 402

Phlebotomy

for hemochromatosis p. 402

Restrictive cardiomyopath

hemochromatosis p. 402

Transcript

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Hemochromatosis is a metabolic disorder where the body absorbs too much iron from the food you eat.

This accumulation of iron leads to elevated iron in the blood and poisoning of tissues in the liver, pancreas, heart, pituitary gland, joints and skin.

The root -chromat- actually refers to color or the darkening of the skin that happens when iron is deposited into it.

If we take a close look at our red blood cells, we’ll notice that they’re loaded with millions of copies of the same exact protein called hemoglobin, which binds to oxygen and turns our blood cells into little oxygen transporters, and basically allow us to move oxygen to all the tissues in our body.

If we take an even closer look at those hemoglobin proteins, we’ll find that they’re made of four heme molecules, which have, right in the middle, iron.

This iron molecule is what binds to oxygen, so without iron, we probably wouldn’t fare too well, right? Right.

Normally, you actually lose a small amount of iron every day, about 1 mg, some in the sweat, some in shedded skin cells, and some in shedded cells in the gastrointestinal tract.

Most of us, through the diet, take in 10-20 mg of iron every day, and absorb about 10% of that, so 1-2 mg, which is perfect!

People with hemochromatosis, though, absorb an unusually high amount of iron, sometimes as much as 4 mg per day, even though you probably only need about 1 mg to even out your losses, right?

You’d think that absorbing more of something is good, but in this case, a net gain of about 3 mg a day comes out to about 1 g per year of excess iron in your body, leading to more than 20 g by age 40!

Most of this iron you hold on to is deposited in your organs, most notably the liver, but also in your pancreas, your heart, joints, skin, and pituitary gland.

This process of depositing iron into organs is called hemosiderosis. But hey, a little hemosiderosis over the course of a lifetime never hurt anyone, right? Wrong!

Unfortunately, all this extra iron does start doing some serious damage because iron in the body is actually pretty good at generating free radicals through the fenton reaction.

The fenton reaction is where molecules of iron 2+ are oxidized by hydrogen peroxide, producing iron 3+ and the hydroxyl radical and hydroxide ion as byproducts; now, iron 3+ can then be reduced back to iron 2+ via hydrogen peroxide again, creating a peroxide radical and a proton, and then the cycle repeats, creating this like endless loop of free radical generation.

Sources

  1. "The transferrin receptor: the cellular iron gate" Metallomics (2017)
  2. "Diagnosis and Treatment of Genetic <i>HFE</i>-Hemochromatosis: The Danish Aspect" Gastroenterology Research (2019)
  3. "Genetics, Genetic Testing, and Management of Hemochromatosis: 15 Years Since Hepcidin" Gastroenterology (2015)
  4. "Robbins Basic Pathology" Elsevier (2017)
  5. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  6. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  7. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  8. "Diagnosis and management of hemochromatosis: 2011 Practice Guideline by the American Association for the Study of Liver Diseases" Hepatology (2011)
  9. "Screening for Hereditary Hemochromatosis: Recommendations from the American College of Physicians" Annals of Internal Medicine (2005)
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