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Hereditary hemochromatosis (HH) is an autosomal recessive disorder most often associated with HFE gene mutations. Patients have increased iron intestinal absorption and iron deposition in several organs, such as the liver, heart, skin, and pancreas. The clinical presentation is usually with nonspecific symptoms and signs such as fatigue and joint pain in patients over 40, abnormal liver function tests, and hypogonadism in men. Diagnosis is made by laboratory testing showing high transferrin saturation or ferritin indicative of iron overload. Other testing includes genetic testing for HFE variants and MRI to quantify liver or heart iron overload. If untreated, HH can lead to cirrhosis, type 2 diabetes, and bronze-colored skin. Other findings depend on the organ(s) involved. Genetic screening is recommended for family members. Management requires phlebotomy (or iron chelation therapy in some cases) to prevent disease progression. The prognosis depends on the severity of iron overload and organ injury at the time of diagnosis and the extent of iron removal. The presence of hepatic fibrosis is a poor prognostic factor.
Last updated: Mar 4, 2024
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Hereditary hemochromatosis Hemochromatosis A disorder of iron metabolism characterized by a triad of hemosiderosis; liver cirrhosis; and diabetes mellitus. It is caused by massive iron deposits in parenchymal cells that may develop after a prolonged increase of iron absorption. Hereditary Hemochromatosis ( HH HH Hereditary hemochromatosis (HH) is an autosomal recessive disorder most often associated with hfe gene mutations. Patients have increased iron intestinal absorption and iron deposition in several organs, such as the liver, heart, skin, and pancreas. The clinical presentation includes the triad of cirrhosis, diabetes, and skin bronzing. Hereditary Hemochromatosis) is an inherited disorder characterized by iron overload Iron overload An excessive accumulation of iron in the body due to a greater than normal absorption of iron from the gastrointestinal tract or from parenteral injection. This may arise from idiopathic hemochromatosis, excessive iron intake, chronic alcoholism, certain types of refractory anemia, or transfusional hemosiderosis. Hereditary Hemochromatosis that results in tissue injury and fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans.
There are 4 types of hereditary hemochromatosis Hemochromatosis A disorder of iron metabolism characterized by a triad of hemosiderosis; liver cirrhosis; and diabetes mellitus. It is caused by massive iron deposits in parenchymal cells that may develop after a prolonged increase of iron absorption. Hereditary Hemochromatosis; classification depends on the mutated gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics.
Types | Mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations | Description |
---|---|---|
1 | HFE | |
2 | 2a: HJV (encodes
hemojuvelin
Hemojuvelin
Hereditary Hemochromatosis) 2b: HAMP (encodes hepcidin Hepcidin Forms of hepcidin, a cationic amphipathic peptide synthesized in the liver as a prepropeptide which is first processed into prohepcidin and then into the biologically active hepcidin forms, including in human the 20-, 22-, and 25-amino acid residue peptide forms. Hepcidin acts as a homeostatic regulators of iron metabolism and also possesses antimicrobial activity. Hereditary Hemochromatosis) |
|
3 | TFR2 | |
4 | SLC40A1 |
It is important to note that causes of iron overload Iron overload An excessive accumulation of iron in the body due to a greater than normal absorption of iron from the gastrointestinal tract or from parenteral injection. This may arise from idiopathic hemochromatosis, excessive iron intake, chronic alcoholism, certain types of refractory anemia, or transfusional hemosiderosis. Hereditary Hemochromatosis may overlap or occur at the same time.
Secondary iron overload Iron overload An excessive accumulation of iron in the body due to a greater than normal absorption of iron from the gastrointestinal tract or from parenteral injection. This may arise from idiopathic hemochromatosis, excessive iron intake, chronic alcoholism, certain types of refractory anemia, or transfusional hemosiderosis. Hereditary Hemochromatosis disorders (acquired):
A common genetic disorder among those of Northern European ancestry[1,2,6,7]
The mechanism of iron overload Iron overload An excessive accumulation of iron in the body due to a greater than normal absorption of iron from the gastrointestinal tract or from parenteral injection. This may arise from idiopathic hemochromatosis, excessive iron intake, chronic alcoholism, certain types of refractory anemia, or transfusional hemosiderosis. Hereditary Hemochromatosis in all 4 types of hemochromatosis Hemochromatosis A disorder of iron metabolism characterized by a triad of hemosiderosis; liver cirrhosis; and diabetes mellitus. It is caused by massive iron deposits in parenchymal cells that may develop after a prolonged increase of iron absorption. Hereditary Hemochromatosis is increased iron absorption Iron absorption Digestion and Absorption by the GI tract; it is regulated by hepcidin Hepcidin Forms of hepcidin, a cationic amphipathic peptide synthesized in the liver as a prepropeptide which is first processed into prohepcidin and then into the biologically active hepcidin forms, including in human the 20-, 22-, and 25-amino acid residue peptide forms. Hepcidin acts as a homeostatic regulators of iron metabolism and also possesses antimicrobial activity. Hereditary Hemochromatosis and results in tissue iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deposition.[11–14]
Certain conditions require a decrease or increase in iron absorption Iron absorption Digestion and Absorption and circulating iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements, a pathway regulated by hepcidin Hepcidin Forms of hepcidin, a cationic amphipathic peptide synthesized in the liver as a prepropeptide which is first processed into prohepcidin and then into the biologically active hepcidin forms, including in human the 20-, 22-, and 25-amino acid residue peptide forms. Hepcidin acts as a homeostatic regulators of iron metabolism and also possesses antimicrobial activity. Hereditary Hemochromatosis:
Men usually present in their 40s or later; women have slower iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements accumulation (presumably due to menstrual blood loss) and present after menopause Menopause Menopause is a physiologic process in women characterized by the permanent cessation of menstruation that occurs after the loss of ovarian activity. Menopause can only be diagnosed retrospectively, after 12 months without menstrual bleeding. Menopause. With patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship being diagnosed earlier since the beginning of the 21st century, end-organ damage secondary to iron overload Iron overload An excessive accumulation of iron in the body due to a greater than normal absorption of iron from the gastrointestinal tract or from parenteral injection. This may arise from idiopathic hemochromatosis, excessive iron intake, chronic alcoholism, certain types of refractory anemia, or transfusional hemosiderosis. Hereditary Hemochromatosis is not often seen in clinical practice.[9,12]
Clinical features of hemochromatosis
Image by Lecturio.HH HH Hereditary hemochromatosis (HH) is an autosomal recessive disorder most often associated with hfe gene mutations. Patients have increased iron intestinal absorption and iron deposition in several organs, such as the liver, heart, skin, and pancreas. The clinical presentation includes the triad of cirrhosis, diabetes, and skin bronzing. Hereditary Hemochromatosis should be considered as a diagnosis in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with elevated liver function tests Liver function tests Liver function tests, also known as hepatic function panels, are one of the most commonly performed screening blood tests. Such tests are also used to detect, evaluate, and monitor acute and chronic liver diseases. Liver Function Tests and abnormal iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements study results. Note that ferritin Ferritin Iron-containing proteins that are widely distributed in animals, plants, and microorganisms. Their major function is to store iron in a nontoxic bioavailable form. Each ferritin molecule consists of ferric iron in a hollow protein shell (apoferritins) made of 24 subunits of various sequences depending on the species and tissue types. Hereditary Hemochromatosis is an acute-phase reactant and can be falsely elevated in other diseases.
Hepatocyte iron accumulation in a patient with hemochromatosis (stained with Perls Prussian blue)
Image: “Grade 3 hepatocyte iron accumulation” by Mathew, J. et al. License: CC BY 3.0.Phlebotomy Phlebotomy The techniques used to draw blood from a vein for diagnostic purposes or for treatment of certain blood disorders such as erythrocytosis, hemochromatosis, polycythemia vera, and porphyria cutanea tarda. Hereditary Hemochromatosis:
Iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements chelating agents:
Erythrocytapheresis:[17]
Additional management[11,15]