Haemochromatosis L5

Question 1

Fe affects organs differently, it is more toxic to some than others. Which is the most sensitive organ to Fe?

Answer 1

Liver

Question 2

Which chromosome is the HFE gene found upon?

Answer 2

Chromosome 6

Question 3

HFE gene

HFE is involved in ____1____ homeostasis.

HFE protein normally limits amount of iron uptake by gut and regulates amount of iron ____2____ in the tissues

Answer 3

1. Iron
2. Stored

Question 4

Name the two common mutations in HFE.

Which one is by far the most common?

Answer 4

C282Y allele (most common)

H63D allele

Question 5

What is the result of an HFE gene mutation?

Answer 5

HFE gene mutations produce altered HFE protein unable to properly regulate iron metabolism which results in excess iron storage in tissues.

Question 6

What does HFE stand for?

Answer 6

High Ferritin

Question 7

What factors exacerbate haemochromatosis? (3)

Answer 7

Alcohol

Diabetes

Obesity

Question 8

Who is more at risk of developing haemochromatosis, men or women?

What is the exception?

Answer 8

Men.

Post-menopausal women are as at risk as men.

Question 9

Why is haemochromatosis generally not evident until 40-60 years of age?

Answer 9

At birth everyone has normal Fe levels and it takes many years to accumulate toxic levels of Fe, hence the typical late life presentation.

Question 10

Fe can accumulate in the heart causing damage and mainly leading to restrictive and dilated ____1____. Just like in the liver, the Fe is causing a fibrotic response. In restrictive ____1____ this leads to the stiffening of the ventricle walls (but not thickened walls) which causes a ____2____ in the pumping efficiency, especially during exercise.

Some patients go on to develop dilated ____1____ where the walls of the ventricle do become thickened (dilated).

Answer 10

1. Cardiomyopathy
2. Reduction/Decrease

Question 11

Name the most widely used dignostic test for haemochromatosis.

Name the most effective dignostic test for haemochromatosis.

Answer 11

Measure level of serum ferritin.

Measure transferrin saturation.

Question 12

Haemochromatosis patients should avoid what foods or dietary factors? (3)

Answer 12

Vitamin C (increases the absorption of iron) and iron supplements

Excessive consumption of alcohol

Raw shellfish

Question 13

In managing haemochromatosis, doctors are looking to prevent the disease before plasma Fe overload, and well before ______ Fe overload.

Answer 13

Tissue

Question 14

Describe the mechanism of action of Hepcidin.

Answer 14

Hepcidin binds to ferroportin, thereby leading to ferroportin degradation and blockage of iron import.

Question 15

Which unusual joints are affected by haemochromatosis-induced arthritis?

Why?

Answer 15

Knuckles and ankles can become quite swollen and painful.

Probably due to Fe disposition into the joint space or when the crystals that normally form cannot be cleared.