Hemochromatosis

Mendelian MONDO:0006507 Pathograph 42 Iron Metabolism Disorders Hereditary Metabolic Diseases

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Mappings

Definitions

Histopathology

Datasets

Models

👪

Inheritance

Autosomal Recessive

Show evidence (2 references)

ORPHA:465508 SUPPORT

"Autosomal recessive"

Orphanet classifies symptomatic HFE-related hemochromatosis as autosomal recessive.

PMID:29620054 SUPPORT

"The most common form of haemochromatosis is due to homozygous mutations (specifically, the C282Y mutation) in HFE"

C282Y homozygosity confirms autosomal recessive inheritance for classic HFE hemochromatosis.

◆

Subtypes

HFE-related hemochromatosis MONDO:0021001

HFE link {'name': 'Autosomal Recessive'}

Classic adult-onset HFE-related hemochromatosis caused most often by HFE p.Cys282Tyr homozygosity, with biochemical, clinical, and non-penetrant phenotypes.

Show evidence (1 reference)

PMID:20301613 SUPPORT Other

"The diagnosis of HFE HC is established in most persons with characteristic laboratory and/or clinical features by identification of HFE p.Cys282Tyr homozygosity."

GeneReviews defines HFE-related hemochromatosis as the HFE homozygous type 1 subtype.

HJV-related juvenile hemochromatosis MONDO:0011216

HJV link {'name': 'Autosomal Recessive'}

Juvenile-onset autosomal recessive hemochromatosis caused by biallelic HJV pathogenic variants, typically presenting before age 30 with severe iron overload and prominent cardiac and endocrine disease.

Show evidence (1 reference)

PMID:35449524 SUPPORT Human Clinical

"Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."

Case report and literature review distinguishes HJV-related type 2A from HAMP-related type 2B.

HAMP-related juvenile hemochromatosis MONDO:0013220

HAMP link {'name': 'Autosomal Recessive'}

Juvenile-onset autosomal recessive hemochromatosis caused by biallelic HAMP pathogenic variants, producing profound hepcidin deficiency and early severe iron overload.

Show evidence (1 reference)

PMID:35449524 SUPPORT Human Clinical

"Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."

Case report and literature review distinguishes HAMP-related type 2B from HJV-related type 2A.

TFR2-related hemochromatosis MONDO:0011417

TFR2 link {'name': 'Autosomal Recessive'}

Autosomal recessive TFR2-related hemochromatosis, with earlier onset than HFE-related disease and iron accumulation in liver, heart, pancreas, and endocrine organs.

Show evidence (1 reference)

PMID:20301523 SUPPORT Other

"The diagnosis of TFR2-HC is established in a proband with biallelic pathogenic variants in TFR2 identified by molecular genetic testing."

GeneReviews defines TFR2-related hemochromatosis as a biallelic TFR2 subtype.

⚙

Pathophysiology

HFE Loss Lowers Hepcidin

Pathogenic HFE variants (most commonly C282Y homozygosity) blunt hepcidin induction, leaving circulating hepcidin inappropriately low relative to body iron stores.

HFE link

regulation of iron ion transport link ⚠ ABNORMAL negative regulation of iron ion transport link ↓ DECREASED

Downstream

Low Hepcidin Leads to Ferroportin Hyperabsorption Inappropriately low hepcidin releases the ferroportin brake on intestinal iron efflux.

Show evidence (1 reference)

PMID:23985001 SUPPORT

"Hereditary hemochromatosis is an inherited iron overload disorder caused by inappropriately low hepcidin secretion leading to increased duodenal absorption of dietary iron, most commonly in C282Y homozygous individuals."

Impaired HFE signaling results in low hepcidin in C282Y homozygotes.

BMP6-Dependent Hepcidin Regulation Defect

Disease-causing BMP6 variants impair an upstream hepcidin regulatory pathway, converging on the same low-hepcidin/ferroportin axis that drives hereditary hemochromatosis.

BMP6 link

regulation of iron ion transport link ⚠ ABNORMAL negative regulation of iron ion transport link ↓ DECREASED

Downstream

Low Hepcidin Leads to Ferroportin Hyperabsorption BMP6-linked hepcidin dysregulation converges on insufficient hepcidin restraint of ferroportin.

Show evidence (3 references)

ORPHA:465508 SUPPORT

"BMP6 | bone morphogenetic protein 6 | hgnc:1073 | Disease-causing germline mutation(s) in"

Orphanet lists BMP6 as a disease-causing gene for symptomatic hemochromatosis.

PMID:26582087 SUPPORT Human Clinical

"Serum levels of hepcidin were inappropriately low in patients."

Human BMP6 mutation carriers with unexplained iron overload had inappropriately low hepcidin.

PMID:26582087 SUPPORT In Vitro

"resulted in defective secretion of BMP6; reduced signaling via SMAD1, SMAD5, and SMAD8; and loss of hepcidin production."

Cell-line functional assays show BMP6 propeptide mutations impair BMP6 secretion, SMAD signaling, and hepcidin production.

Non-HFE Hepcidin Deficiency

HJV, HAMP, and TFR2 pathogenic variants cause non-HFE hemochromatosis by disrupting hepcidin production or hepcidin-pathway signaling, leading to severe or earlier-onset iron overload.

HJV link HAMP link TFR2 link

regulation of iron ion transport link ⚠ ABNORMAL negative regulation of iron ion transport link ↓ DECREASED

Downstream

Low Hepcidin Leads to Ferroportin Hyperabsorption Non-HFE hepcidin-pathway defects converge on inadequate hepcidin restraint of ferroportin-mediated iron export.

Show evidence (3 references)

PMID:20301349 SUPPORT Other

"HAMP- and HJV-related hemochromatosis (HC) are characterized by onset of severe iron overload occurring typically in the first to third decades of life."

GeneReviews summarizes juvenile HAMP/HJV-related hemochromatosis as early severe iron overload.

PMID:20301349 SUPPORT Other

"The diagnosis of HAMP- or HJV-related HC is established in a proband with clinical and laboratory features of iron overload and biallelic pathogenic variants in HAMP or HJV identified by molecular genetic testing."

GeneReviews links HAMP and HJV biallelic variants to the non-HFE hemochromatosis mechanism.

PMID:20301523 SUPPORT Other

"TFR2-related hemochromatosis (TFR2-HC) is characterized by increased intestinal iron absorption resulting in iron accumulation in the liver, heart, pancreas, and endocrine organs."

GeneReviews links TFR2-related hemochromatosis to increased intestinal iron absorption and multi-organ iron accumulation.

Low Hepcidin Leads to Ferroportin Hyperabsorption

Suppressed hepcidin fails to internalize and degrade ferroportin on enterocytes, so dietary iron efflux into plasma is unchecked, driving systemic iron overload.

enterocyte link

iron ion export across plasma membrane link ↑ INCREASED positive regulation of iron ion transport link ↑ INCREASED

Downstream

Systemic Iron Overload Increased intestinal ferroportin-mediated export expands the plasma iron pool.

Show evidence (1 reference)

PMID:23985001 PARTIAL

"Hereditary hemochromatosis is an inherited iron overload disorder caused by inappropriately low hepcidin secretion leading to increased duodenal absorption of dietary iron"

Low hepcidin permits unregulated ferroportin-mediated iron export from the gut.

Systemic Iron Overload

Hepcidin insufficiency causes iron hyperabsorption, plasma iron-pool expansion, toxic non-transferrin-bound iron formation, and iron accumulation across the liver, heart, endocrine glands, joints, and other tissues.

iron ion transport link ↑ INCREASED intracellular iron ion homeostasis link ⚠ ABNORMAL

Downstream

Hepatic Iron Toxicity Increased gut iron transfer elevates circulating iron and drives hepatic deposition.

Cardiac Iron Deposition Chronic plasma iron loading promotes myocardial iron accumulation.

Pancreatic Iron Toxicity Systemic iron excess leads to iron deposition in pancreatic islets.

Pituitary-Gonadal Iron Toxicity Systemic iron loading affects endocrine tissues, especially pituitary gonadotropes.

Iron-Associated Arthropathy Toxic iron species and joint deposition contribute to hemochromatosis arthropathy.

Dermal Iron and Melanin Deposition Iron loading contributes to bronze skin pigmentation.

Iron-Associated Bone Fragility Iron deposition in bone and gonadal injury contribute to low bone density and fracture risk.

Systemic Iron Overload Symptoms Multi-organ iron overload produces constitutional symptoms including fatigue and weight loss.

Show evidence (2 references)

PMID:39644049 SUPPORT Human Clinical

"hepcidin insufficiency in the context of normal erythropoiesis, iron hyperabsorption, and expansion of the plasma iron pool with increased transferrin saturation"

Recent review defines hemochromatosis as hepcidin insufficiency with iron hyperabsorption and plasma iron-pool expansion.

PMID:39644049 SUPPORT Human Clinical

"This results in the formation of toxic non-transferrin-bound iron, which ultimately accumulates in multiple organs, including the liver, heart, endocrine glands, and joints."

The expanded iron pool forms toxic non-transferrin-bound iron and accumulates in multiple target organs.

Hepatic Iron Toxicity

Excess iron deposits in hepatocytes leading to oxidative stress, lipid peroxidation, and hepatocellular damage. Progressive iron accumulation causes fibrosis and can lead to cirrhosis and hepatocellular carcinoma.

hepatocyte link

cellular response to oxidative stress link intrinsic apoptotic signaling pathway in response to oxidative stress link extracellular matrix organization link

Downstream

Hepatomegaly Hepatocyte injury and remodeling contribute to progressive liver enlargement.

Elevated Hepatic Transaminases Hepatocellular injury releases circulating hepatic transaminases.

Abdominal Pain Hepatic iron loading and liver enlargement can manifest as abdominal pain.

Cirrhosis Chronic iron-mediated hepatocellular injury and fibrotic remodeling can progress to cirrhosis.

Hepatocellular Carcinoma Advanced iron-mediated liver injury and carcinogenic iron stress increase HCC risk.

Show evidence (1 reference)

PMID:37763705 PARTIAL

"The key organ that is affected by iron overload is the liver, suffering from fibrosis, cirrhosis or hepatocellular carcinoma"

Liver iron overload drives fibrotic injury and malignant risk.

Cardiac Iron Deposition

Iron accumulation in cardiomyocytes causes oxidative damage and impaired contractility, leading to cardiomyopathy and cardiac failure, particularly dilated cardiomyopathy.

cardiac muscle cell link

cellular response to oxidative stress link regulation of heart contraction link response to iron ion link

Downstream

Cardiomyopathy Oxidative myocardial injury and contractile dysfunction manifest as cardiomyopathy.

Show evidence (1 reference)

PMID:35449524 PARTIAL

"Hemochromatosis type 2 or juvenile hemochromatosis has an early onset of severe iron overload resulting in organ manifestation such as liver fibrosis, cirrhosis, cardiomyopathy, arthropathy, hypogonadism, diabetes"

Early severe iron overload includes cardiomyopathy, consistent with cardiac iron toxicity.

Pancreatic Iron Toxicity

Iron deposition in pancreatic beta cells causes oxidative damage and impaired insulin secretion, leading to diabetes mellitus ("bronze diabetes").

type B pancreatic cell link

cellular response to oxidative stress link negative regulation of insulin secretion link response to iron(II) ion link

Downstream

Diabetes Mellitus Beta-cell dysfunction from iron toxicity impairs insulin output and drives diabetes.

Hyperglycemia Impaired beta-cell insulin secretion first manifests as elevated blood glucose.

Show evidence (1 reference)

PMID:38886778 PARTIAL

"Magnetic resonance imaging showed iron deposition in the liver, spleen, and pancreas, along with cirrhosis and splenomegaly."

Imaging confirms pancreatic iron deposition contributing to endocrine dysfunction.

Pituitary-Gonadal Iron Toxicity

Iron deposition in endocrine tissues, especially the pituitary gland, injures gonadotrope and thyrotrope function, causing hypogonadotropic hypogonadism with reproductive manifestations and occasional secondary hypothyroidism.

endocrine cell link

cellular response to oxidative stress link ↑ INCREASED response to iron ion link ↑ INCREASED

Downstream

Hypogonadotropic Hypogonadism Pituitary iron deposition disrupts gonadotropin output.

Erectile Dysfunction Hypogonadism from pituitary iron toxicity can impair male sexual function.

Amenorrhea Gonadotropin deficiency from pituitary iron toxicity can suppress menstrual cycling.

Hypothyroidism Pituitary siderosis can also cause secondary hypothyroidism in severe hemochromatosis.

Show evidence (2 references)

PMID:32327622 SUPPORT Human Clinical

"iron deposition in parenchymal cells, particularly those of the endocrine system and cardiomyocytes"

Juvenile hemochromatosis case review identifies endocrine tissues as key sites of iron deposition.

PMID:32327622 SUPPORT Human Clinical

"The more intense and early accumulation of iron in juvenile hemochromatosis seems to be responsible for the greater severity and diversification of affected organs, especially the heart and pituitary gland"

The case report specifically highlights pituitary involvement as a driver of endocrine disease.

Iron-Associated Arthropathy

Iron overload damages joints and periarticular tissues, producing the characteristic metacarpophalangeal arthropathy and contributing to excess joint replacement risk.

cellular response to oxidative stress link ↑ INCREASED response to iron ion link ↑ INCREASED

Downstream

Arthropathy Joint iron-associated tissue injury manifests as hemochromatosis arthropathy.

Show evidence (2 references)

PMID:39644049 SUPPORT Human Clinical

"accumulates in multiple organs, including the liver, heart, endocrine glands, and joints"

Review identifies joints as target sites for toxic iron accumulation.

PMID:31989186 SUPPORT Human Clinical

"Parenchyma damage may be a consequence of iron deposition in affected organs (e.g., liver, pancreas, gonads) as well as bones and joints, leading to osteoporosis with increased fracture risk and arthropathy."

Human bone-microarchitecture study links iron deposition in bones and joints to arthropathy.

Dermal Iron and Melanin Deposition

Iron accumulation contributes to increased melanin and iron deposition in the dermis, producing the classic bronze-gray hyperpigmentation.

response to iron ion link ↑ INCREASED

Downstream

Skin Hyperpigmentation Dermal iron and pigment deposition produce bronze hyperpigmentation.

Show evidence (2 references)

ORPHA:465508 SUPPORT

"increase in skin pigmentation"

Orphanet lists increased skin pigmentation among characteristic signs of symptomatic hemochromatosis.

PMID:32327622 SUPPORT Human Clinical

"other affected organs included the liver, pancreas, and skin and to a lesser extent, the joints"

Juvenile hemochromatosis review identifies skin as an iron-overload target organ.

Iron-Associated Bone Fragility

Iron overload affects bone and gonadal endocrine function, reducing bone density and increasing fracture risk in hemochromatosis.

bone remodeling link ⚠ ABNORMAL response to iron ion link ↑ INCREASED

Downstream

Osteoporosis Iron-associated bone remodeling abnormalities manifest as osteoporosis.

Decreased Muscle Mass Hypogonadism and systemic iron-overload effects contribute to reduced muscle mass.

Show evidence (2 references)

PMID:31989186 SUPPORT Human Clinical

Human study connects iron deposition in bones, joints, and gonads with osteoporosis and fracture risk.

PMID:31989186 SUPPORT Human Clinical

"Cortical volumetric bone mineral density (Ct.BMD) and cortical thickness (Ct.Th) were reduced"

Hemochromatosis patients had reduced cortical bone mineral density and thickness.

Systemic Iron Overload Symptoms

Chronic multi-organ iron overload causes constitutional symptoms, including fatigue, weakness, lethargy, and unintentional weight loss.

response to iron ion link ↑ INCREASED

Downstream

Fatigue Progressive systemic iron overload manifests as chronic fatigue.

Weight Loss Advanced systemic iron overload can produce unintentional weight loss.

Show evidence (2 references)

ORPHA:465508 SUPPORT

"abdominal pain, weakness, lethargy, weight loss, elevated serum aminotransferase levels"

Orphanet lists constitutional symptoms among signs of symptomatic hemochromatosis.

PMID:30244162 SUPPORT Human Clinical

"Genetic hemochromatosis is an inherited disorder that leads to progressive iron overload in the body. It results in chronic fatigue"

Long-term clinical cohort summary links progressive iron overload to chronic fatigue.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

Cardiovascular 1

Cardiomyopathy OCCASIONAL Cardiomyopathy (HP:0001638)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0001638 | Cardiomyopathy | Occasional (29-5%)"

Orphanet lists cardiomyopathy as occasional in symptomatic HFE hemochromatosis.

PMID:35449524 PARTIAL

Juvenile hemochromatosis case describes cardiomyopathy among manifestations.

Digestive 3

Hepatomegaly FREQUENT Hepatomegaly (HP:0002240)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0002240 | Hepatomegaly | Frequent (79-30%)"

Orphanet lists hepatomegaly as frequent in symptomatic HFE hemochromatosis.

PMID:37168645 PARTIAL

"One of the most serious clinical characteristics associated with early-onset iron overload is liver disease with eventual cirrhosis"

Liver involvement early in disease course leads to enlargement and progression to cirrhosis.

Cirrhosis OCCASIONAL Cirrhosis (HP:0001394)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0001394 | Cirrhosis | Occasional (29-5%)"

Orphanet lists cirrhosis as occasional in symptomatic HFE hemochromatosis.

PMID:35662478 SUPPORT Human Clinical

"Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."

EASL guidelines identify cirrhosis as a preventable complication.

PMID:38479735 SUPPORT Human Clinical

"20.3% vs 8.3% had liver disease"

UK Biobank shows significantly excess liver disease in male C282Y homozygotes.

Hepatocellular Carcinoma OCCASIONAL Hepatocellular carcinoma (HP:0001402)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0001402 | Hepatocellular carcinoma | Occasional (29-5%)"

Orphanet lists hepatocellular carcinoma as occasional in symptomatic HFE hemochromatosis.

PMID:23985001 SUPPORT Human Clinical

"Iron overload is being recognized to play a carcinogenic role in hepatocellular carcinoma and other cancers"

Review highlights iron-driven carcinogenesis as a recognized mechanism in HCC.

PMID:37121243 SUPPORT Human Clinical

"Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."

Lancet seminar lists liver cancer as a major preventable complication.

Endocrine 3

Diabetes Mellitus OCCASIONAL Diabetes mellitus (HP:0000819)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0000819 | Diabetes mellitus | Occasional (29-5%)"

Orphanet lists diabetes mellitus as occasional in symptomatic HFE hemochromatosis.

PMID:35662478 SUPPORT Human Clinical

"Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."

EASL guidelines list diabetes as a preventable complication of hemochromatosis.

PMID:38886778 PARTIAL Human Clinical

"The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year, with a history of knee joint pain, diabetes and skin pigmentation."

Diabetes reported as part of the hemochromatosis presentation.

Hypogonadotropic Hypogonadism OCCASIONAL Hypogonadotropic hypogonadism (HP:0000044)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0000044 | Hypogonadotropic hypogonadism | Occasional (29-5%)"

Orphanet lists hypogonadotropic hypogonadism as occasional in symptomatic HFE hemochromatosis.

PMID:36644615 PARTIAL

"Pituitary haemochromatosis is an endocrine disorder caused by the accumulation of iron due to a lack of absorption during haemochromatosis."

Pituitary iron deposition disrupts gonadotropin signaling leading to hypogonadism.

PMID:32327622 SUPPORT Human Clinical

"The most classical clinical findings are hypogonadotropic hypogonadism, cardiomyopathy, liver fibrosis, glycemic changes, arthropathy and skin pigmentation."

Hypogonadotropic hypogonadism is listed as a classical finding in hemochromatosis.

Hypothyroidism OCCASIONAL Hypothyroidism (HP:0000821)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0000821 | Hypothyroidism | Occasional (29-5%)"

Orphanet lists hypothyroidism as occasional in symptomatic HFE hemochromatosis.

PMID:32327622 SUPPORT Human Clinical

"The patient was diagnosed with juvenile hemochromatosis presenting with hypogonadotropic hypogonadism, cardiomyopathy, insulin-dependent diabetes mellitus, and secondary hypothyroidism."

Case report documents secondary hypothyroidism as a manifestation of hemochromatosis.

Genitourinary 1

Amenorrhea OCCASIONAL Amenorrhea (HP:0000141)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0000141 | Amenorrhea | Occasional (29-5%)"

Orphanet lists amenorrhea as occasional in symptomatic HFE hemochromatosis.

PMID:32327622 SUPPORT Human Clinical

"she presented with arthralgia, diffuse abdominal pain, adynamia, hair loss, darkening of the skin and amenorrhea"

Case report documents amenorrhea in a patient with juvenile hemochromatosis.

Integument 1

Skin Hyperpigmentation FREQUENT Generalized bronze hyperpigmentation (HP:0007574)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0007574 | Generalized bronze hyperpigmentation | Frequent (79-30%)"

Orphanet lists bronze hyperpigmentation as frequent in symptomatic HFE hemochromatosis.

PMID:38886778 PARTIAL

"The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year, with a history of knee joint pain, diabetes and skin pigmentation."

Case report documents skin pigmentation in ferroportin-related hemochromatosis.

Metabolism 2

Hyperglycemia FREQUENT Hyperglycemia (HP:0003074)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0003074 | Hyperglycemia | Frequent (79-30%)"

Orphanet lists hyperglycemia as frequent in symptomatic HFE hemochromatosis, distinct from overt diabetes.

PMID:29620054 SUPPORT Human Clinical

"the accumulation of iron in parenchymal cells, particularly hepatocytes, pancreatic cells and cardiomyocytes"

Pancreatic iron accumulation underlies the glycemic abnormalities in hemochromatosis.

Elevated Hepatic Transaminases Elevated circulating hepatic transaminase concentration (HP:0002910)

Show evidence (1 reference)

PMID:38886778 SUPPORT Human Clinical

"The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year"

Persistent liver enzyme elevation is a common presenting finding in hemochromatosis.

Musculoskeletal 2

Arthropathy FREQUENT Arthropathy (HP:0003040)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0003040 | Arthropathy | Frequent (79-30%)"

Orphanet lists arthropathy as frequent in symptomatic HFE hemochromatosis.

PMID:32728396 SUPPORT Human Clinical

"The frequency of radiographic MCP2-3 arthropathy was 37.6% (95% CI 0.28-0.48)."

Cross-sectional study of 93 HH patients confirms MCP joint arthropathy in over a third.

PMID:38479735 SUPPORT Human Clinical

"27.9% vs 17.1% had joint replacements"

UK Biobank shows excess joint replacements in male C282Y homozygotes.

Osteoporosis OCCASIONAL Osteoporosis (HP:0000939)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0000939 | Osteoporosis | Occasional (29-5%)"

Orphanet lists osteoporosis as occasional in symptomatic HFE hemochromatosis.

PMID:32728396 SUPPORT Human Clinical

"The frequency of bone fragility was 20.4% (95% CI 0.13-0.30). Bone fragility was independently associated with hepatic cirrhosis"

Cross-sectional study of 93 HH patients found bone fragility in 20.4%, linked to cirrhosis.

PMID:31989186 SUPPORT Human Clinical

Iron deposition affects bone leading to osteoporosis and increased fracture risk.

Constitutional 2

Fatigue FREQUENT Fatigue (HP:0012378)

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0012378 | Fatigue | Frequent (79-30%)"

Orphanet lists fatigue as frequent in symptomatic HFE hemochromatosis.

PMID:39337031 SUPPORT Human Clinical

"The HH patients exhibited significantly worse fatigue across all the scales."

Fatigue questionnaires show higher fatigue burden in HH compared with controls.

PMID:30244162 SUPPORT Human Clinical

"It results in chronic fatigue and in potential liver (cirrhosis), pancreas (diabetes) and joint (arthritis) damage in adulthood."

Long-term cohort notes chronic fatigue as a characteristic manifestation of genetic hemochromatosis.

Abdominal Pain FREQUENT Abdominal pain (HP:0002027)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0002027 | Abdominal pain | Frequent (79-30%)"

Orphanet lists abdominal pain as frequent in symptomatic HFE hemochromatosis.

PMID:32327622 SUPPORT Human Clinical

"she presented with arthralgia, diffuse abdominal pain, adynamia, hair loss, darkening of the skin and amenorrhea"

Case report of hemochromatosis includes abdominal pain as a presenting symptom.

Growth 1

Weight Loss OCCASIONAL Weight loss (HP:0001824)

Show evidence (2 references)

ORPHA:465508 SUPPORT

"HP:0001824 | Weight loss | Occasional (29-5%)"

Orphanet lists weight loss as occasional in symptomatic HFE hemochromatosis.

ORPHA:465508 SUPPORT

"abdominal pain, weakness, lethargy, weight loss, elevated serum aminotransferase levels"

Orphanet definition of symptomatic HFE hemochromatosis includes weight loss among characteristic signs.

Other 2

Decreased Muscle Mass FREQUENT Decreased muscle mass (HP:0003199)

Show evidence (1 reference)

ORPHA:465508 SUPPORT

"HP:0003199 | Decreased muscle mass | Frequent (79-30%)"

Orphanet lists decreased muscle mass as frequent in symptomatic HFE hemochromatosis.

Erectile Dysfunction OCCASIONAL Erectile dysfunction (HP:0100639)

Show evidence (1 reference)

ORPHA:465508 SUPPORT

"HP:0100639 | Erectile dysfunction | Occasional (29-5%)"

Orphanet lists erectile dysfunction as occasional in symptomatic HFE hemochromatosis.

🧬

Genetic Associations

HFE Mutations (Causative)

Autosomal Recessive

Show evidence (4 references)

PMID:23985001 SUPPORT

"most commonly in C282Y homozygous individuals"

Review confirms C282Y homozygosity as the most common cause of hereditary hemochromatosis.

ORPHA:465508 SUPPORT

"HFE | homeostatic iron regulator | hgnc:4886 | Disease-causing germline mutation(s) in"

Orphanet confirms HFE as the causative gene for symptomatic HFE hemochromatosis.

PMID:33259166 SUPPORT Human Clinical

"C282Y gene homozygosity is implicated in 80%-95% of cases of hereditary hemochromatosis."

Large cohort study confirms C282Y homozygosity accounts for the majority of HH cases.

+ 1 more reference

BMP6 Mutations (Causative)

Autosomal Dominant

Show evidence (3 references)

ORPHA:465508 SUPPORT

"BMP6 | bone morphogenetic protein 6 | hgnc:1073 | Disease-causing germline mutation(s) in"

Orphanet lists BMP6 as a disease-causing gene for symptomatic HFE hemochromatosis.

PMID:26582087 SUPPORT Human Clinical

"We identified 3 heterozygous missense mutations in BMP6 (p.Pro95Ser, p.Leu96Pro, and p.Gln113Glu) in 6 unrelated patients with unexplained iron overload"

Human cohort study identified heterozygous BMP6 missense mutations in patients with unexplained iron overload.

PMID:26582087 SUPPORT Human Clinical

"Family studies indicated dominant transmission."

The BMP6 propeptide mutation study reported dominant transmission in family studies.

HJV Mutations (Causative)

Autosomal Recessive

Show evidence (2 references)

PMID:35449524 SUPPORT Human Clinical

"Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."

Case report and review identifies HJV as the type 2A juvenile hemochromatosis gene.

PMID:35449524 SUPPORT Human Clinical

"We identified the variant c.309C > G (p.Phe103Leu) in the HJV gene in the homozygous state in the patient."

The reported juvenile hemochromatosis case had a homozygous HJV variant.

HAMP Mutations (Causative)

Autosomal Recessive

Show evidence (2 references)

PMID:35449524 SUPPORT Human Clinical

"Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."

Case report and review identifies HAMP as the type 2B juvenile hemochromatosis gene.

PMID:20301349 SUPPORT Other

"biallelic pathogenic variants in HAMP or HJV identified by molecular genetic testing."

GeneReviews establishes biallelic HAMP variants as diagnostic for HAMP-related hemochromatosis.

TFR2 Mutations (Causative)

Autosomal Recessive

Show evidence (2 references)

PMID:20301523 SUPPORT Other

"The diagnosis of TFR2-HC is established in a proband with biallelic pathogenic variants in TFR2 identified by molecular genetic testing."

GeneReviews establishes biallelic TFR2 variants as diagnostic for TFR2-related hemochromatosis.

PMID:29620054 SUPPORT Human Clinical

"Non-HFE forms of haemochromatosis due to mutations in HAMP, HJV or TFR2 are much rarer."

Primer identifies TFR2 among rare non-HFE hemochromatosis genes.

💊

Treatments

Phlebotomy (Therapeutic Venesection)

Action: phlebotomy Ontology label: Phlebotomy NCIT:C28221

Regular blood removal is the primary treatment, which reduces iron stores by requiring the body to use iron for new red blood cell production. Initially weekly until iron stores normalize, then maintenance every 2-3 months.

Mechanism Target:

INHIBITS Systemic Iron Overload — Periodic blood removal depletes body iron stores and prevents downstream organ injury.

Show evidence (1 reference)

PMID:35662478 SUPPORT Human Clinical

"Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."

EASL guideline supports phlebotomy as an iron-depletion intervention that prevents downstream complications.

Show evidence (5 references)

PMID:23985001 SUPPORT

"Phlebotomy remains the mainstay of treatment and new treatments being studied include erythrocytapheresis and 'mini-hepcidins'."

This review confirms phlebotomy as the standard first-line treatment for hereditary hemochromatosis.

PMID:38886778 SUPPORT

"Four patients with organ damage in the present study received therapeutic phlebotomy, alleviating clinical symptoms and improving in transferrin saturation and serum ferritin."

Phlebotomy improved iron indices and symptoms in a ferroportin hemochromatosis pedigree.

PMID:37121243 SUPPORT

"Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."

Seminar notes phlebotomy prevents cirrhosis and mortality when started early.

+ 2 more references

Iron Chelation Therapy

Action: iron chelation therapy Ontology label: chelator agent therapy MAXO:0001223

Deferoxamine or oral chelators (deferasirox, deferiprone) are used when phlebotomy is contraindicated or insufficient, such as in patients with anemia.

Mechanism Target:

INHIBITS Systemic Iron Overload — Chelator therapy removes excess iron when phlebotomy is not feasible.

Show evidence (1 reference)

PMID:29620054 SUPPORT Human Clinical

"The mainstay therapy is phlebotomy, although iron chelation can be used in some patients."

Primer supports chelation as an alternative means of treating systemic iron overload in selected patients.

Show evidence (2 references)

PMID:19727383 PARTIAL

"Because secondary hemochromatosis is due to hereditary or acquired anemia, phlebotomy is not a suitable means of removing excess iron in this situation. Rather, the treatment is based on the targeted elimination of iron by means of iron chelators."

Secondary hemochromatosis requires chelation when phlebotomy is not feasible.

PMID:29620054 SUPPORT

"The mainstay therapy is phlebotomy, although iron chelation can be used in some patients."

Primer notes chelation as an alternative for selected patients.

Dietary Modification

Action: dietary intervention MAXO:0000088

Avoiding iron supplements, limiting vitamin C intake (which enhances iron absorption), and reducing alcohol consumption to protect the liver.

Mechanism Target:

MODULATES Systemic Iron Overload — Dietary and alcohol changes can reduce iron loading pressure and improve iron indices.

Show evidence (1 reference)

PMID:38361672 SUPPORT Human Clinical

"This patient was counseled on lifestyle modifications which included abstaining from alcohol and reducing iron and vitamin C intake. As a result, his iron panel parameters improved."

Case report shows lifestyle changes improving iron panel parameters.

Show evidence (1 reference)

PMID:38361672 PARTIAL

"This patient was counseled on lifestyle modifications which included abstaining from alcohol and reducing iron and vitamin C intake. As a result, his iron panel parameters improved."

Lifestyle changes in alcohol and dietary iron/Vitamin C improved iron indices.

Screening of Family Members

Action: genetic counseling MAXO:0000079

Genetic testing of first-degree relatives is recommended given the autosomal recessive inheritance pattern and the benefits of early intervention.

Mechanism Target:

MODULATES Systemic Iron Overload — Family screening enables early diagnosis and treatment before systemic iron overload causes irreversible complications.

Show evidence (1 reference)

PMID:37121243 SUPPORT Human Clinical

"Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."

Early genetic testing in at-risk relatives supports prevention through earlier iron-depletion therapy.

Show evidence (1 reference)

PMID:37121243 PARTIAL

"Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."

Emphasizes early genetic testing to enable preventive treatment.

🔬

Biochemical Markers

Elevated Transferrin Saturation (elevated)

Pathograph Readouts

Readout Of Systemic Iron Overload Positive Diagnostic

Elevated transferrin saturation reports hepcidin-insufficient iron hyperabsorption and expansion of the plasma iron pool.

Show evidence (1 reference)

PMID:39644049 SUPPORT Human Clinical

"iron hyperabsorption, and expansion of the plasma iron pool with increased transferrin saturation, the diagnostic hallmark of the disease"

Review explicitly ties increased transferrin saturation to plasma iron-pool expansion and diagnostic use.

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0012463 | Elevated transferrin saturation | Very frequent (99-80%)"

Orphanet lists elevated transferrin saturation as very frequent in symptomatic HFE hemochromatosis.

PMID:39644049 SUPPORT Human Clinical

"iron hyperabsorption, and expansion of the plasma iron pool with increased transferrin saturation, the diagnostic hallmark of the disease"

Recent review confirms elevated TSAT as the diagnostic hallmark of hemochromatosis.

PMID:35662478 SUPPORT Human Clinical

"Haemochromatosis is characterised by elevated transferrin saturation (TSAT) and progressive iron loading that mainly affects the liver."

EASL guidelines define hemochromatosis by elevated TSAT.

Increased Circulating Ferritin (elevated)

Pathograph Readouts

Readout Of Systemic Iron Overload Positive Diagnostic

Elevated ferritin reflects increased iron stores accompanying systemic iron overload.

Show evidence (1 reference)

PMID:23985001 SUPPORT Human Clinical

"This can result in elevated serum ferritin, iron deposition in various organs and ultimately end-organ damage"

Elevated ferritin accompanies organ iron deposition and end-organ damage in hereditary hemochromatosis.

Predicts Hepatic Iron Toxicity Positive Prognostic

Very high ferritin marks increased risk of cirrhosis and mortality in C282Y homozygotes.

Show evidence (1 reference)

PMID:23985001 SUPPORT Human Clinical

"is associated with an increased risk of cirrhosis and mortality in C282Y homozygotes"

The review links high serum ferritin with cirrhosis and mortality risk.

Show evidence (3 references)

ORPHA:465508 SUPPORT

"HP:0003281 | Increased circulating ferritin concentration | Very frequent (99-80%)"

Orphanet lists increased ferritin as very frequent in symptomatic HFE hemochromatosis.

PMID:23985001 SUPPORT Human Clinical

"This can result in elevated serum ferritin, iron deposition in various organs and ultimately end-organ damage"

Elevated serum ferritin accompanies iron deposition in hereditary hemochromatosis.

PMID:35662478 SUPPORT Human Clinical

"TSAT >45% and ferritin >200 μg/L in females and TSAT >50% and ferritin >300 μg/L in males and postmenopausal women"

EASL guidelines specify sex-stratified ferritin thresholds for diagnosis.

🔀

Differential Diagnoses

Conditions with similar clinical presentations that must be differentiated from Hemochromatosis:

Secondary/Transfusional Iron Overload

Overlapping Features Iron accumulation from chronic transfusions or ineffective erythropoiesis can mimic hereditary hemochromatosis but occurs in anemic patients where phlebotomy is not feasible.

Distinguishing Features

History of chronic transfusions or underlying anemia (e.g., thalassemia, MDS)
Phlebotomy contraindicated due to anemia; chelation preferred
Iron loading often involves reticuloendothelial system in addition to parenchyma

Show evidence (1 reference)

PMID:19727383 SUPPORT

Highlights anemia/transfusion-related iron overload where chelation is required instead of phlebotomy.

Ferroportin Disease (SLC40A1-Related Hemochromatosis)

Overlapping Features Autosomal dominant iron overload from gain-of-function SLC40A1 variants can present with high ferritin and iron deposition, necessitating distinction from HFE-hemochromatosis.

Distinguishing Features

Often autosomal dominant inheritance pattern
Elevated ferritin with variable transferrin saturation; iron may accumulate in macrophages and liver
Genetic testing reveals SLC40A1 variants affecting ferroportin

Show evidence (1 reference)

PMID:38886778 SUPPORT

"SLC40A1-related haemochromatosis is associated with gain-of-function mutations in the SLC40A1 gene, which encodes ferroportin."

Establishes ferroportin-associated iron overload as a distinct entity to differentiate.

🔬

Clinical Trials

NCT04202965 PHASE_II COMPLETED

Open-label study of rusfertide (PTG-300), a hepcidin mimetic peptide, in adults with HFE-related hereditary hemochromatosis. Assessed effects on transferrin saturation, serum iron, and phlebotomy requirements.

Show evidence (1 reference)

clinicaltrials:NCT04202965 SUPPORT

"This study will be conducted at multiple sites and every patient will get treated with PTG-300. The objective of the study is to assess the effect of PTG-300 in treating adult hereditary hemochromatosis patients."

Completed Phase 2 trial of hepcidin mimetic targeting the core hepcidin insufficiency pathway in HFE-H.

{ }

Source YAML

click to show

name: Hemochromatosis
creation_date: '2026-01-09T07:07:01Z'
updated_date: '2026-05-19T00:02:52Z'
category: Mendelian
disease_term:
  preferred_term: hereditary hemochromatosis
  term:
    id: MONDO:0006507
    label: hereditary hemochromatosis
parents:
- Iron Metabolism Disorders
- Hereditary Metabolic Diseases
has_subtypes:
- name: Type 1
  display_name: HFE-related hemochromatosis
  description: >-
    Classic adult-onset HFE-related hemochromatosis caused most often by HFE
    p.Cys282Tyr homozygosity, with biochemical, clinical, and non-penetrant
    phenotypes.
  subtype_term:
    preferred_term: hemochromatosis type 1
    term:
      id: MONDO:0021001
      label: hemochromatosis type 1
  genes:
  - preferred_term: HFE
    term:
      id: hgnc:4886
      label: HFE
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:20301613
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of HFE HC is established in most persons with characteristic laboratory and/or clinical features by identification of HFE p.Cys282Tyr homozygosity."
    explanation: GeneReviews defines HFE-related hemochromatosis as the HFE homozygous type 1 subtype.
- name: Type 2A
  display_name: HJV-related juvenile hemochromatosis
  description: >-
    Juvenile-onset autosomal recessive hemochromatosis caused by biallelic HJV
    pathogenic variants, typically presenting before age 30 with severe iron
    overload and prominent cardiac and endocrine disease.
  subtype_term:
    preferred_term: hemochromatosis type 2A
    term:
      id: MONDO:0011216
      label: hemochromatosis type 2A
  genes:
  - preferred_term: HJV
    term:
      id: hgnc:4887
      label: HJV
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:35449524
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."
    explanation: Case report and literature review distinguishes HJV-related type 2A from HAMP-related type 2B.
- name: Type 2B
  display_name: HAMP-related juvenile hemochromatosis
  description: >-
    Juvenile-onset autosomal recessive hemochromatosis caused by biallelic HAMP
    pathogenic variants, producing profound hepcidin deficiency and early severe
    iron overload.
  subtype_term:
    preferred_term: hemochromatosis type 2B
    term:
      id: MONDO:0013220
      label: hemochromatosis type 2B
  genes:
  - preferred_term: HAMP
    term:
      id: hgnc:15598
      label: HAMP
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:35449524
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."
    explanation: Case report and literature review distinguishes HAMP-related type 2B from HJV-related type 2A.
- name: Type 3
  display_name: TFR2-related hemochromatosis
  description: >-
    Autosomal recessive TFR2-related hemochromatosis, with earlier onset than
    HFE-related disease and iron accumulation in liver, heart, pancreas, and
    endocrine organs.
  subtype_term:
    preferred_term: hemochromatosis type 3
    term:
      id: MONDO:0011417
      label: hemochromatosis type 3
  genes:
  - preferred_term: TFR2
    term:
      id: hgnc:11762
      label: TFR2
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:20301523
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of TFR2-HC is established in a proband with biallelic pathogenic variants in TFR2 identified by molecular genetic testing."
    explanation: GeneReviews defines TFR2-related hemochromatosis as a biallelic TFR2 subtype.
inheritance:
- name: Autosomal Recessive
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "Autosomal recessive"
    explanation: Orphanet classifies symptomatic HFE-related hemochromatosis as autosomal recessive.
  - reference: PMID:29620054
    supports: SUPPORT
    snippet: "The most common form of haemochromatosis is due to homozygous mutations (specifically, the C282Y mutation) in HFE"
    explanation: C282Y homozygosity confirms autosomal recessive inheritance for classic HFE hemochromatosis.
progression:
- phase: Pre-symptomatic iron loading
  age_range: 20-40 years
  notes: >-
    Iron accumulates silently over decades. Symptoms typically manifest between
    40-60 years in men; later in women due to menstrual iron losses.
    Non-HFE forms (juvenile hemochromatosis) can present in adolescence.
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "Age of onset: Adult"
    explanation: Orphanet classifies the symptomatic form of HFE hemochromatosis as adult-onset.
  - reference: PMID:33259166
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The mean age of diagnosis was 49.1 years."
    explanation: Newfoundland cohort of C282Y homozygotes shows typical middle-age diagnosis.
prevalence:
- population: White primary care patients in Rochester, New York
  percentage: 5.4 per 1,000
  notes: >-
    Screening-based U.S. estimates show hereditary hemochromatosis is relatively
    common among white adults, though prevalence varies substantially by
    ancestry and clinical penetrance is incomplete.
  evidence:
  - reference: PMID:9867748
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The prevalence of clinically proven and biopsy-proven hemochromatosis combined was 4.5 per 1000 (95% CI, 3.3 to 5.8 per 1000) in the total sample and 5.4 per 1000 (CI, 4.0 to 7.1 per 1000) in white persons."
    explanation: Large primary-care screening study provides a quantitative prevalence estimate for clinically ascertained hereditary hemochromatosis in white adults.
- population: Northern European ancestry (C282Y homozygosity prevalence)
  percentage: 1 in 200
  notes: >-
    Nearly 1 in 200 people of Northern European descent carry C282Y homozygosity,
    though clinical penetrance is incomplete, especially in females.
  evidence:
  - reference: PMID:39644049
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most common form is HFE-hemochromatosis (HFE-H) due to p.Cys282Tyr (C282Y) homozygosity, present in nearly 1 in 200 people of Northern European descent but characterized by low penetrance, particularly in females."
    explanation: Recent review quantifies genetic prevalence of HFE-H in Northern Europeans.
  - reference: ORPHA:139498
    supports: SUPPORT
    snippet: "NON RARE IN EUROPE: Hemochromatosis type 1"
    explanation: Orphanet classifies HFE-related hemochromatosis as non-rare in Europe.
- population: UK Biobank male C282Y homozygotes
  percentage: 56.4% diagnosed by age 80
  notes: >-
    Cumulative incidence of hemochromatosis diagnosis in male C282Y homozygotes
    reaches 56.4% by age 80 in a large prospective UK cohort.
  evidence:
  - reference: PMID:38479735
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "12.1% of p.C282Y+/+ males had baseline (mean age 57 years) haemochromatosis diagnoses, with a cumulative incidence of 56.4% at age 80 years."
    explanation: UK Biobank prospective data shows high cumulative diagnosis rate in male homozygotes.
pathophysiology:
- name: HFE Loss Lowers Hepcidin
  description: >
    Pathogenic HFE variants (most commonly C282Y homozygosity) blunt hepcidin induction,
    leaving circulating hepcidin inappropriately low relative to body iron stores.
  genes:
  - preferred_term: HFE
    term:
      id: hgnc:4886
      label: HFE
  evidence:
  - reference: PMID:23985001
    reference_title: "Diagnosis and treatment of hereditary hemochromatosis: an update."
    supports: SUPPORT
    snippet: "Hereditary hemochromatosis is an inherited iron overload disorder caused by inappropriately low hepcidin secretion leading to increased duodenal absorption of dietary iron, most commonly in C282Y homozygous individuals."
    explanation: Impaired HFE signaling results in low hepcidin in C282Y homozygotes.
  biological_processes:
  - preferred_term: regulation of iron ion transport
    term:
      id: GO:0034756
      label: regulation of iron ion transport
    modifier: ABNORMAL
  - preferred_term: negative regulation of iron ion transport
    term:
      id: GO:0034757
      label: negative regulation of iron ion transport
    modifier: DECREASED
  downstream:
  - target: Low Hepcidin Leads to Ferroportin Hyperabsorption
    description: Inappropriately low hepcidin releases the ferroportin brake on intestinal iron efflux.

- name: BMP6-Dependent Hepcidin Regulation Defect
  description: >
    Disease-causing BMP6 variants impair an upstream hepcidin regulatory pathway,
    converging on the same low-hepcidin/ferroportin axis that drives hereditary
    hemochromatosis.
  genes:
  - preferred_term: BMP6
    term:
      id: hgnc:1073
      label: BMP6
  biological_processes:
  - preferred_term: regulation of iron ion transport
    term:
      id: GO:0034756
      label: regulation of iron ion transport
    modifier: ABNORMAL
  - preferred_term: negative regulation of iron ion transport
    term:
      id: GO:0034757
      label: negative regulation of iron ion transport
    modifier: DECREASED
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "BMP6 | bone morphogenetic protein 6 | hgnc:1073 | Disease-causing germline mutation(s) in"
    explanation: Orphanet lists BMP6 as a disease-causing gene for symptomatic hemochromatosis.
  - reference: PMID:26582087
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Serum levels of hepcidin were inappropriately low in patients."
    explanation: Human BMP6 mutation carriers with unexplained iron overload had inappropriately low hepcidin.
  - reference: PMID:26582087
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "resulted in defective secretion of BMP6; reduced signaling via SMAD1, SMAD5, and SMAD8; and loss of hepcidin production."
    explanation: Cell-line functional assays show BMP6 propeptide mutations impair BMP6 secretion, SMAD signaling, and hepcidin production.
  downstream:
  - target: Low Hepcidin Leads to Ferroportin Hyperabsorption
    description: BMP6-linked hepcidin dysregulation converges on insufficient hepcidin restraint of ferroportin.

- name: Non-HFE Hepcidin Deficiency
  description: >
    HJV, HAMP, and TFR2 pathogenic variants cause non-HFE hemochromatosis by
    disrupting hepcidin production or hepcidin-pathway signaling, leading to
    severe or earlier-onset iron overload.
  genes:
  - preferred_term: HJV
    term:
      id: hgnc:4887
      label: HJV
  - preferred_term: HAMP
    term:
      id: hgnc:15598
      label: HAMP
  - preferred_term: TFR2
    term:
      id: hgnc:11762
      label: TFR2
  biological_processes:
  - preferred_term: regulation of iron ion transport
    term:
      id: GO:0034756
      label: regulation of iron ion transport
    modifier: ABNORMAL
  - preferred_term: negative regulation of iron ion transport
    term:
      id: GO:0034757
      label: negative regulation of iron ion transport
    modifier: DECREASED
  evidence:
  - reference: PMID:20301349
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HAMP- and HJV-related hemochromatosis (HC) are characterized by onset of severe iron overload occurring typically in the first to third decades of life."
    explanation: GeneReviews summarizes juvenile HAMP/HJV-related hemochromatosis as early severe iron overload.
  - reference: PMID:20301349
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of HAMP- or HJV-related HC is established in a proband with clinical and laboratory features of iron overload and biallelic pathogenic variants in HAMP or HJV identified by molecular genetic testing."
    explanation: GeneReviews links HAMP and HJV biallelic variants to the non-HFE hemochromatosis mechanism.
  - reference: PMID:20301523
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "TFR2-related hemochromatosis (TFR2-HC) is characterized by increased intestinal iron absorption resulting in iron accumulation in the liver, heart, pancreas, and endocrine organs."
    explanation: GeneReviews links TFR2-related hemochromatosis to increased intestinal iron absorption and multi-organ iron accumulation.
  downstream:
  - target: Low Hepcidin Leads to Ferroportin Hyperabsorption
    description: Non-HFE hepcidin-pathway defects converge on inadequate hepcidin restraint of ferroportin-mediated iron export.

- name: Low Hepcidin Leads to Ferroportin Hyperabsorption
  description: >
    Suppressed hepcidin fails to internalize and degrade ferroportin on enterocytes, so
    dietary iron efflux into plasma is unchecked, driving systemic iron overload.
  evidence:
  - reference: PMID:23985001
    reference_title: "Diagnosis and treatment of hereditary hemochromatosis: an update."
    supports: PARTIAL
    snippet: "Hereditary hemochromatosis is an inherited iron overload disorder caused by inappropriately low hepcidin secretion leading to increased duodenal absorption of dietary iron"
    explanation: Low hepcidin permits unregulated ferroportin-mediated iron export from the gut.
  biological_processes:
  - preferred_term: iron ion export across plasma membrane
    term:
      id: GO:1903988
      label: iron ion export across plasma membrane
    modifier: INCREASED
  - preferred_term: positive regulation of iron ion transport
    term:
      id: GO:0034758
      label: positive regulation of iron ion transport
    modifier: INCREASED
  cell_types:
  - preferred_term: enterocyte
    term:
      id: CL:0000584
      label: enterocyte
  downstream:
  - target: Systemic Iron Overload
    description: Increased intestinal ferroportin-mediated export expands the plasma iron pool.
- name: Systemic Iron Overload
  description: >
    Hepcidin insufficiency causes iron hyperabsorption, plasma iron-pool expansion,
    toxic non-transferrin-bound iron formation, and iron accumulation across the
    liver, heart, endocrine glands, joints, and other tissues.
  biological_processes:
  - preferred_term: iron ion transport
    term:
      id: GO:0006826
      label: iron ion transport
    modifier: INCREASED
  - preferred_term: intracellular iron ion homeostasis
    term:
      id: GO:0006879
      label: intracellular iron ion homeostasis
    modifier: ABNORMAL
  chemical_entities:
  - preferred_term: iron
    term:
      id: CHEBI:18248
      label: iron atom
    modifier: INCREASED
  evidence:
  - reference: PMID:39644049
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "hepcidin insufficiency in the context of normal erythropoiesis, iron hyperabsorption, and expansion of the plasma iron pool with increased transferrin saturation"
    explanation: Recent review defines hemochromatosis as hepcidin insufficiency with iron hyperabsorption and plasma iron-pool expansion.
  - reference: PMID:39644049
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This results in the formation of toxic non-transferrin-bound iron, which ultimately accumulates in multiple organs, including the liver, heart, endocrine glands, and joints."
    explanation: The expanded iron pool forms toxic non-transferrin-bound iron and accumulates in multiple target organs.
  downstream:
  - target: Hepatic Iron Toxicity
    description: Increased gut iron transfer elevates circulating iron and drives hepatic deposition.
  - target: Cardiac Iron Deposition
    description: Chronic plasma iron loading promotes myocardial iron accumulation.
  - target: Pancreatic Iron Toxicity
    description: Systemic iron excess leads to iron deposition in pancreatic islets.
  - target: Pituitary-Gonadal Iron Toxicity
    description: Systemic iron loading affects endocrine tissues, especially pituitary gonadotropes.
  - target: Iron-Associated Arthropathy
    description: Toxic iron species and joint deposition contribute to hemochromatosis arthropathy.
  - target: Dermal Iron and Melanin Deposition
    description: Iron loading contributes to bronze skin pigmentation.
  - target: Iron-Associated Bone Fragility
    description: Iron deposition in bone and gonadal injury contribute to low bone density and fracture risk.
  - target: Systemic Iron Overload Symptoms
    description: Multi-organ iron overload produces constitutional symptoms including fatigue and weight loss.
- name: Hepatic Iron Toxicity
  description: >
    Excess iron deposits in hepatocytes leading to oxidative stress, lipid peroxidation,
    and hepatocellular damage. Progressive iron accumulation causes fibrosis and can
    lead to cirrhosis and hepatocellular carcinoma.
  evidence:
  - reference: PMID:37763705
    reference_title: "A \"Mix and Match\" in Hemochromatosis-A Case Report and Literature Focus on the Liver."
    supports: PARTIAL
    snippet: "The key organ that is affected by iron overload is the liver, suffering from fibrosis, cirrhosis or hepatocellular carcinoma"
    explanation: Liver iron overload drives fibrotic injury and malignant risk.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: cellular response to oxidative stress
    term:
      id: GO:0034599
      label: cellular response to oxidative stress
  - preferred_term: intrinsic apoptotic signaling pathway in response to oxidative stress
    term:
      id: GO:0008631
      label: intrinsic apoptotic signaling pathway in response to oxidative stress
  - preferred_term: extracellular matrix organization
    term:
      id: GO:0030198
      label: extracellular matrix organization
  downstream:
  - target: Hepatomegaly
    description: Hepatocyte injury and remodeling contribute to progressive liver enlargement.
  - target: Elevated Hepatic Transaminases
    description: Hepatocellular injury releases circulating hepatic transaminases.
  - target: Abdominal Pain
    description: Hepatic iron loading and liver enlargement can manifest as abdominal pain.
  - target: Cirrhosis
    description: Chronic iron-mediated hepatocellular injury and fibrotic remodeling can progress to cirrhosis.
  - target: Hepatocellular Carcinoma
    description: Advanced iron-mediated liver injury and carcinogenic iron stress increase HCC risk.
- name: Cardiac Iron Deposition
  description: >
    Iron accumulation in cardiomyocytes causes oxidative damage and impaired contractility,
    leading to cardiomyopathy and cardiac failure, particularly dilated cardiomyopathy.
  evidence:
  - reference: PMID:35449524
    reference_title: "Juvenile Hemochromatosis due to a Homozygous Variant in the HJV Gene."
    supports: PARTIAL
    snippet: "Hemochromatosis type 2 or juvenile hemochromatosis has an early onset of severe iron overload resulting in organ manifestation such as liver fibrosis, cirrhosis, cardiomyopathy, arthropathy, hypogonadism, diabetes"
    explanation: Early severe iron overload includes cardiomyopathy, consistent with cardiac iron toxicity.
  cell_types:
  - preferred_term: cardiac muscle cell
    term:
      id: CL:0000746
      label: cardiac muscle cell
  biological_processes:
  - preferred_term: cellular response to oxidative stress
    term:
      id: GO:0034599
      label: cellular response to oxidative stress
  - preferred_term: regulation of heart contraction
    term:
      id: GO:0008016
      label: regulation of heart contraction
  - preferred_term: response to iron ion
    term:
      id: GO:0010039
      label: response to iron ion
  downstream:
  - target: Cardiomyopathy
    description: Oxidative myocardial injury and contractile dysfunction manifest as cardiomyopathy.
- name: Pancreatic Iron Toxicity
  description: >
    Iron deposition in pancreatic beta cells causes oxidative damage and impaired insulin
    secretion, leading to diabetes mellitus ("bronze diabetes").
  evidence:
  - reference: PMID:38886778
    reference_title: "SLC40A1-related hemochromatosis associated with a p.Y333H mutation in mainland China: a pedigree report and literature review."
    supports: PARTIAL
    snippet: "Magnetic resonance imaging showed iron deposition in the liver, spleen, and pancreas, along with cirrhosis and splenomegaly."
    explanation: Imaging confirms pancreatic iron deposition contributing to endocrine dysfunction.
  cell_types:
  - preferred_term: type B pancreatic cell
    term:
      id: CL:0000169
      label: type B pancreatic cell
  biological_processes:
  - preferred_term: cellular response to oxidative stress
    term:
      id: GO:0034599
      label: cellular response to oxidative stress
  - preferred_term: negative regulation of insulin secretion
    term:
      id: GO:0046676
      label: negative regulation of insulin secretion
  - preferred_term: response to iron(II) ion
    term:
      id: GO:0010040
      label: response to iron(II) ion
  downstream:
  - target: Diabetes Mellitus
    description: Beta-cell dysfunction from iron toxicity impairs insulin output and drives diabetes.
  - target: Hyperglycemia
    description: Impaired beta-cell insulin secretion first manifests as elevated blood glucose.
- name: Pituitary-Gonadal Iron Toxicity
  description: >
    Iron deposition in endocrine tissues, especially the pituitary gland, injures
    gonadotrope and thyrotrope function, causing hypogonadotropic hypogonadism
    with reproductive manifestations and occasional secondary hypothyroidism.
  evidence:
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "iron deposition in parenchymal cells, particularly those of the endocrine system and cardiomyocytes"
    explanation: Juvenile hemochromatosis case review identifies endocrine tissues as key sites of iron deposition.
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The more intense and early accumulation of iron in juvenile hemochromatosis seems to be responsible for the greater severity and diversification of affected organs, especially the heart and pituitary gland"
    explanation: The case report specifically highlights pituitary involvement as a driver of endocrine disease.
  cell_types:
  - preferred_term: endocrine cell
    term:
      id: CL:0000163
      label: endocrine cell
  biological_processes:
  - preferred_term: cellular response to oxidative stress
    term:
      id: GO:0034599
      label: cellular response to oxidative stress
    modifier: INCREASED
  - preferred_term: response to iron ion
    term:
      id: GO:0010039
      label: response to iron ion
    modifier: INCREASED
  downstream:
  - target: Hypogonadotropic Hypogonadism
    description: Pituitary iron deposition disrupts gonadotropin output.
  - target: Erectile Dysfunction
    description: Hypogonadism from pituitary iron toxicity can impair male sexual function.
  - target: Amenorrhea
    description: Gonadotropin deficiency from pituitary iron toxicity can suppress menstrual cycling.
  - target: Hypothyroidism
    description: Pituitary siderosis can also cause secondary hypothyroidism in severe hemochromatosis.
- name: Iron-Associated Arthropathy
  description: >
    Iron overload damages joints and periarticular tissues, producing the characteristic
    metacarpophalangeal arthropathy and contributing to excess joint replacement risk.
  evidence:
  - reference: PMID:39644049
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "accumulates in multiple organs, including the liver, heart, endocrine glands, and joints"
    explanation: Review identifies joints as target sites for toxic iron accumulation.
  - reference: PMID:31989186
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Parenchyma damage may be a consequence of iron deposition in affected organs (e.g., liver, pancreas, gonads) as well as bones and joints, leading to osteoporosis with increased fracture risk and arthropathy."
    explanation: Human bone-microarchitecture study links iron deposition in bones and joints to arthropathy.
  biological_processes:
  - preferred_term: cellular response to oxidative stress
    term:
      id: GO:0034599
      label: cellular response to oxidative stress
    modifier: INCREASED
  - preferred_term: response to iron ion
    term:
      id: GO:0010039
      label: response to iron ion
    modifier: INCREASED
  downstream:
  - target: Arthropathy
    description: Joint iron-associated tissue injury manifests as hemochromatosis arthropathy.
- name: Dermal Iron and Melanin Deposition
  description: >
    Iron accumulation contributes to increased melanin and iron deposition in the
    dermis, producing the classic bronze-gray hyperpigmentation.
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "increase in skin pigmentation"
    explanation: Orphanet lists increased skin pigmentation among characteristic signs of symptomatic hemochromatosis.
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "other affected organs included the liver, pancreas, and skin and to a lesser extent, the joints"
    explanation: Juvenile hemochromatosis review identifies skin as an iron-overload target organ.
  biological_processes:
  - preferred_term: response to iron ion
    term:
      id: GO:0010039
      label: response to iron ion
    modifier: INCREASED
  downstream:
  - target: Skin Hyperpigmentation
    description: Dermal iron and pigment deposition produce bronze hyperpigmentation.
- name: Iron-Associated Bone Fragility
  description: >
    Iron overload affects bone and gonadal endocrine function, reducing bone density
    and increasing fracture risk in hemochromatosis.
  evidence:
  - reference: PMID:31989186
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Parenchyma damage may be a consequence of iron deposition in affected organs (e.g., liver, pancreas, gonads) as well as bones and joints, leading to osteoporosis with increased fracture risk and arthropathy."
    explanation: Human study connects iron deposition in bones, joints, and gonads with osteoporosis and fracture risk.
  - reference: PMID:31989186
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cortical volumetric bone mineral density (Ct.BMD) and cortical thickness (Ct.Th) were reduced"
    explanation: Hemochromatosis patients had reduced cortical bone mineral density and thickness.
  biological_processes:
  - preferred_term: bone remodeling
    term:
      id: GO:0046849
      label: bone remodeling
    modifier: ABNORMAL
  - preferred_term: response to iron ion
    term:
      id: GO:0010039
      label: response to iron ion
    modifier: INCREASED
  downstream:
  - target: Osteoporosis
    description: Iron-associated bone remodeling abnormalities manifest as osteoporosis.
  - target: Decreased Muscle Mass
    description: Hypogonadism and systemic iron-overload effects contribute to reduced muscle mass.
- name: Systemic Iron Overload Symptoms
  description: >
    Chronic multi-organ iron overload causes constitutional symptoms, including
    fatigue, weakness, lethargy, and unintentional weight loss.
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "abdominal pain, weakness, lethargy, weight loss, elevated serum aminotransferase levels"
    explanation: Orphanet lists constitutional symptoms among signs of symptomatic hemochromatosis.
  - reference: PMID:30244162
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Genetic hemochromatosis is an inherited disorder that leads to progressive iron overload in the body. It results in chronic fatigue"
    explanation: Long-term clinical cohort summary links progressive iron overload to chronic fatigue.
  biological_processes:
  - preferred_term: response to iron ion
    term:
      id: GO:0010039
      label: response to iron ion
    modifier: INCREASED
  downstream:
  - target: Fatigue
    description: Progressive systemic iron overload manifests as chronic fatigue.
  - target: Weight Loss
    description: Advanced systemic iron overload can produce unintentional weight loss.
phenotypes:
- name: Hepatomegaly
  category: Hepatic
  frequency: FREQUENT
  description: >
    Enlarged liver due to iron accumulation in hepatocytes, often the earliest
    detectable physical finding.
  phenotype_term:
    preferred_term: hepatomegaly
    term:
      id: HP:0002240
      label: Hepatomegaly
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0002240 | Hepatomegaly | Frequent (79-30%)"
    explanation: Orphanet lists hepatomegaly as frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:37168645
    supports: PARTIAL
    snippet: "One of the most serious clinical characteristics associated with early-onset iron overload is liver disease with eventual cirrhosis"
    explanation: Liver involvement early in disease course leads to enlargement and progression to cirrhosis.
- name: Skin Hyperpigmentation
  category: Dermatologic
  frequency: FREQUENT
  description: >
    Bronze or grayish skin discoloration due to increased melanin and iron deposition
    in the dermis, a classic feature of hemochromatosis.
  phenotype_term:
    preferred_term: generalized bronze hyperpigmentation
    term:
      id: HP:0007574
      label: Generalized bronze hyperpigmentation
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0007574 | Generalized bronze hyperpigmentation | Frequent (79-30%)"
    explanation: Orphanet lists bronze hyperpigmentation as frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:38886778
    supports: PARTIAL
    snippet: "The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year, with a history of knee joint pain, diabetes and skin pigmentation."
    explanation: Case report documents skin pigmentation in ferroportin-related hemochromatosis.
- name: Diabetes Mellitus
  category: Endocrine
  frequency: OCCASIONAL
  description: >
    Development of diabetes due to pancreatic beta cell destruction from iron toxicity,
    historically called "bronze diabetes."
  phenotype_term:
    preferred_term: diabetes mellitus
    term:
      id: HP:0000819
      label: Diabetes mellitus
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0000819 | Diabetes mellitus | Occasional (29-5%)"
    explanation: Orphanet lists diabetes mellitus as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:35662478
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."
    explanation: EASL guidelines list diabetes as a preventable complication of hemochromatosis.
  - reference: PMID:38886778
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year, with a history of knee joint pain, diabetes and skin pigmentation."
    explanation: Diabetes reported as part of the hemochromatosis presentation.
- name: Arthropathy
  category: Musculoskeletal
  frequency: FREQUENT
  description: >
    Joint pain and swelling, particularly affecting the second and third
    metacarpophalangeal joints, due to iron and calcium pyrophosphate deposition.
    Arthropathy is one of the most common and refractory manifestations
    of hemochromatosis, often persisting despite iron depletion.
  phenotype_term:
    preferred_term: arthropathy
    term:
      id: HP:0003040
      label: Arthropathy
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0003040 | Arthropathy | Frequent (79-30%)"
    explanation: Orphanet lists arthropathy as frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:32728396
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The frequency of radiographic MCP2-3 arthropathy was 37.6% (95% CI 0.28-0.48)."
    explanation: Cross-sectional study of 93 HH patients confirms MCP joint arthropathy in over a third.
  - reference: PMID:38479735
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "27.9% vs 17.1% had joint replacements"
    explanation: UK Biobank shows excess joint replacements in male C282Y homozygotes.
- name: Cardiomyopathy
  category: Cardiac
  frequency: OCCASIONAL
  description: >
    Heart muscle disease due to iron deposition in cardiomyocytes, which can lead
    to heart failure and arrhythmias.
  phenotype_term:
    preferred_term: cardiomyopathy
    term:
      id: HP:0001638
      label: Cardiomyopathy
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0001638 | Cardiomyopathy | Occasional (29-5%)"
    explanation: Orphanet lists cardiomyopathy as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:35449524
    supports: PARTIAL
    snippet: "Hemochromatosis type 2 or juvenile hemochromatosis has an early onset of severe iron overload resulting in organ manifestation such as liver fibrosis, cirrhosis, cardiomyopathy, arthropathy, hypogonadism, diabetes"
    explanation: Juvenile hemochromatosis case describes cardiomyopathy among manifestations.
- name: Hypogonadotropic Hypogonadism
  category: Endocrine
  frequency: OCCASIONAL
  description: >
    Decreased gonadal function due to iron deposition in the pituitary gland,
    leading to reduced libido, erectile dysfunction, and testicular atrophy.
  phenotype_term:
    preferred_term: hypogonadotropic hypogonadism
    term:
      id: HP:0000044
      label: Hypogonadotropic hypogonadism
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0000044 | Hypogonadotropic hypogonadism | Occasional (29-5%)"
    explanation: Orphanet lists hypogonadotropic hypogonadism as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:36644615
    supports: PARTIAL
    snippet: "Pituitary haemochromatosis is an endocrine disorder caused by the accumulation of iron due to a lack of absorption during haemochromatosis."
    explanation: Pituitary iron deposition disrupts gonadotropin signaling leading to hypogonadism.
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most classical clinical findings are hypogonadotropic hypogonadism, cardiomyopathy, liver fibrosis, glycemic changes, arthropathy and skin pigmentation."
    explanation: Hypogonadotropic hypogonadism is listed as a classical finding in hemochromatosis.
- name: Fatigue
  category: Constitutional
  frequency: FREQUENT
  description: >
    Chronic tiredness and weakness, one of the most common and earliest symptoms
    of hemochromatosis.
  phenotype_term:
    preferred_term: fatigue
    term:
      id: HP:0012378
      label: Fatigue
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0012378 | Fatigue | Frequent (79-30%)"
    explanation: Orphanet lists fatigue as frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:39337031
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The HH patients exhibited significantly worse fatigue across all the scales."
    explanation: Fatigue questionnaires show higher fatigue burden in HH compared with controls.
  - reference: PMID:30244162
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It results in chronic fatigue and in potential liver (cirrhosis), pancreas (diabetes) and joint (arthritis) damage in adulthood."
    explanation: Long-term cohort notes chronic fatigue as a characteristic manifestation of genetic hemochromatosis.
- name: Hyperglycemia
  category: Endocrine
  frequency: FREQUENT
  description: >
    Elevated blood glucose levels due to iron-mediated pancreatic beta cell
    dysfunction, preceding the development of overt diabetes mellitus.
  phenotype_term:
    preferred_term: hyperglycemia
    term:
      id: HP:0003074
      label: Hyperglycemia
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0003074 | Hyperglycemia | Frequent (79-30%)"
    explanation: Orphanet lists hyperglycemia as frequent in symptomatic HFE hemochromatosis, distinct from overt diabetes.
  - reference: PMID:29620054
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the accumulation of iron in parenchymal cells, particularly hepatocytes, pancreatic cells and cardiomyocytes"
    explanation: Pancreatic iron accumulation underlies the glycemic abnormalities in hemochromatosis.
- name: Decreased Muscle Mass
  category: Musculoskeletal
  frequency: FREQUENT
  description: >
    Loss of muscle mass and wasting, associated with systemic iron overload,
    hypogonadism, and chronic disease effects.
  phenotype_term:
    preferred_term: decreased muscle mass
    term:
      id: HP:0003199
      label: Decreased muscle mass
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0003199 | Decreased muscle mass | Frequent (79-30%)"
    explanation: Orphanet lists decreased muscle mass as frequent in symptomatic HFE hemochromatosis.
- name: Abdominal Pain
  category: Gastrointestinal
  frequency: FREQUENT
  description: >
    Abdominal pain, particularly in the right upper quadrant, is a common presenting
    symptom reflecting hepatic iron loading and liver capsule distension.
  phenotype_term:
    preferred_term: abdominal pain
    term:
      id: HP:0002027
      label: Abdominal pain
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0002027 | Abdominal pain | Frequent (79-30%)"
    explanation: Orphanet lists abdominal pain as frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "she presented with arthralgia, diffuse abdominal pain, adynamia, hair loss, darkening of the skin and amenorrhea"
    explanation: Case report of hemochromatosis includes abdominal pain as a presenting symptom.
- name: Cirrhosis
  category: Hepatic
  frequency: OCCASIONAL
  description: >
    Progressive hepatic fibrosis leading to cirrhosis, a major complication of
    untreated hemochromatosis. Cirrhosis greatly increases the risk of hepatocellular
    carcinoma and is the leading cause of disease-related mortality.
  phenotype_term:
    preferred_term: cirrhosis
    term:
      id: HP:0001394
      label: Cirrhosis
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0001394 | Cirrhosis | Occasional (29-5%)"
    explanation: Orphanet lists cirrhosis as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:35662478
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."
    explanation: EASL guidelines identify cirrhosis as a preventable complication.
  - reference: PMID:38479735
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "20.3% vs 8.3% had liver disease"
    explanation: UK Biobank shows significantly excess liver disease in male C282Y homozygotes.
- name: Hepatocellular Carcinoma
  category: Hepatic
  frequency: OCCASIONAL
  description: >
    Liver cancer arising in the setting of cirrhosis or advanced fibrosis due
    to chronic iron-mediated hepatic injury. Patients with cirrhosis require
    ongoing HCC surveillance.
  phenotype_term:
    preferred_term: hepatocellular carcinoma
    term:
      id: HP:0001402
      label: Hepatocellular carcinoma
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0001402 | Hepatocellular carcinoma | Occasional (29-5%)"
    explanation: Orphanet lists hepatocellular carcinoma as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:23985001
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Iron overload is being recognized to play a carcinogenic role in hepatocellular carcinoma and other cancers"
    explanation: Review highlights iron-driven carcinogenesis as a recognized mechanism in HCC.
  - reference: PMID:37121243
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."
    explanation: Lancet seminar lists liver cancer as a major preventable complication.
- name: Osteoporosis
  category: Musculoskeletal
  frequency: OCCASIONAL
  description: >
    Reduced bone mineral density and altered bone microarchitecture due to
    iron-mediated effects on osteoblasts, hypogonadism, and hepatic dysfunction.
    Bone fragility is associated with hepatic cirrhosis in hemochromatosis.
  phenotype_term:
    preferred_term: osteoporosis
    term:
      id: HP:0000939
      label: Osteoporosis
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0000939 | Osteoporosis | Occasional (29-5%)"
    explanation: Orphanet lists osteoporosis as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:32728396
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The frequency of bone fragility was 20.4% (95% CI 0.13-0.30). Bone fragility was independently associated with hepatic cirrhosis"
    explanation: Cross-sectional study of 93 HH patients found bone fragility in 20.4%, linked to cirrhosis.
  - reference: PMID:31989186
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Parenchyma damage may be a consequence of iron deposition in affected organs (e.g., liver, pancreas, gonads) as well as bones and joints, leading to osteoporosis with increased fracture risk and arthropathy."
    explanation: Iron deposition affects bone leading to osteoporosis and increased fracture risk.
- name: Weight Loss
  category: Constitutional
  frequency: OCCASIONAL
  description: >
    Unintentional weight loss can occur as part of the systemic manifestations
    of advanced hemochromatosis, often accompanying fatigue and weakness.
  phenotype_term:
    preferred_term: weight loss
    term:
      id: HP:0001824
      label: Weight loss
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0001824 | Weight loss | Occasional (29-5%)"
    explanation: Orphanet lists weight loss as occasional in symptomatic HFE hemochromatosis.
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "abdominal pain, weakness, lethargy, weight loss, elevated serum aminotransferase levels"
    explanation: Orphanet definition of symptomatic HFE hemochromatosis includes weight loss among characteristic signs.
- name: Hypothyroidism
  category: Endocrine
  frequency: OCCASIONAL
  description: >
    Iron deposition in the thyroid gland or pituitary can cause hypothyroidism,
    including secondary hypothyroidism from pituitary iron loading.
  phenotype_term:
    preferred_term: hypothyroidism
    term:
      id: HP:0000821
      label: Hypothyroidism
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0000821 | Hypothyroidism | Occasional (29-5%)"
    explanation: Orphanet lists hypothyroidism as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The patient was diagnosed with juvenile hemochromatosis presenting with hypogonadotropic hypogonadism, cardiomyopathy, insulin-dependent diabetes mellitus, and secondary hypothyroidism."
    explanation: Case report documents secondary hypothyroidism as a manifestation of hemochromatosis.
- name: Erectile Dysfunction
  category: Reproductive
  frequency: OCCASIONAL
  description: >
    Impaired sexual function in males due to hypogonadotropic hypogonadism
    from pituitary iron deposition.
  phenotype_term:
    preferred_term: erectile dysfunction
    term:
      id: HP:0100639
      label: Erectile dysfunction
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0100639 | Erectile dysfunction | Occasional (29-5%)"
    explanation: Orphanet lists erectile dysfunction as occasional in symptomatic HFE hemochromatosis.
- name: Amenorrhea
  category: Reproductive
  frequency: OCCASIONAL
  description: >
    Loss of menstrual periods in affected females due to iron deposition in
    the pituitary gland causing hypogonadotropic hypogonadism.
  phenotype_term:
    preferred_term: amenorrhea
    term:
      id: HP:0000141
      label: Amenorrhea
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0000141 | Amenorrhea | Occasional (29-5%)"
    explanation: Orphanet lists amenorrhea as occasional in symptomatic HFE hemochromatosis.
  - reference: PMID:32327622
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "she presented with arthralgia, diffuse abdominal pain, adynamia, hair loss, darkening of the skin and amenorrhea"
    explanation: Case report documents amenorrhea in a patient with juvenile hemochromatosis.
- name: Elevated Hepatic Transaminases
  category: Laboratory
  description: >
    Elevated serum aminotransferase levels (AST, ALT) reflecting hepatocellular
    injury from iron-mediated oxidative damage.
  phenotype_term:
    preferred_term: elevated circulating hepatic transaminase concentration
    term:
      id: HP:0002910
      label: Elevated circulating hepatic transaminase concentration
  evidence:
  - reference: PMID:38886778
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year"
    explanation: Persistent liver enzyme elevation is a common presenting finding in hemochromatosis.
treatments:
- name: Phlebotomy (Therapeutic Venesection)
  description: >
    Regular blood removal is the primary treatment, which reduces iron stores by
    requiring the body to use iron for new red blood cell production. Initially
    weekly until iron stores normalize, then maintenance every 2-3 months.
  treatment_term:
    preferred_term: phlebotomy
    term:
      id: NCIT:C28221
      label: Phlebotomy
  target_mechanisms:
  - target: Systemic Iron Overload
    treatment_effect: INHIBITS
    description: Periodic blood removal depletes body iron stores and prevents downstream organ injury.
    evidence:
    - reference: PMID:35662478
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."
      explanation: EASL guideline supports phlebotomy as an iron-depletion intervention that prevents downstream complications.
  evidence:
  - reference: PMID:23985001
    reference_title: "Diagnosis and treatment of hereditary hemochromatosis: an update."
    supports: SUPPORT
    snippet: "Phlebotomy remains the mainstay of treatment and new treatments being studied include erythrocytapheresis and 'mini-hepcidins'."
    explanation: "This review confirms phlebotomy as the standard first-line treatment for hereditary hemochromatosis."
  - reference: PMID:38886778
    reference_title: "SLC40A1-related hemochromatosis associated with a p.Y333H mutation in mainland China: a pedigree report and literature review."
    supports: SUPPORT
    snippet: "Four patients with organ damage in the present study received therapeutic phlebotomy, alleviating clinical symptoms and improving in transferrin saturation and serum ferritin."
    explanation: Phlebotomy improved iron indices and symptoms in a ferroportin hemochromatosis pedigree.
  - reference: PMID:37121243
    reference_title: "Haemochromatosis."
    supports: SUPPORT
    snippet: "Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."
    explanation: Seminar notes phlebotomy prevents cirrhosis and mortality when started early.
  - reference: PMID:35662478
    reference_title: "EASL Clinical Practice Guidelines on haemochromatosis."
    supports: SUPPORT
    snippet: "Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications."
    explanation: EASL guideline highlights phlebotomy as preventive for multi-organ complications.
  - reference: PMID:5339192
    reference_title: "The treatment of hemochromatosis by phlebotomy."
    supports: PARTIAL
    snippet: "The treatment of hemochromatosis by phlebotomy."
    explanation: Early clinical report established phlebotomy as definitive iron removal.
- name: Iron Chelation Therapy
  description: >
    Deferoxamine or oral chelators (deferasirox, deferiprone) are used when
    phlebotomy is contraindicated or insufficient, such as in patients with anemia.
  target_mechanisms:
  - target: Systemic Iron Overload
    treatment_effect: INHIBITS
    description: Chelator therapy removes excess iron when phlebotomy is not feasible.
    evidence:
    - reference: PMID:29620054
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The mainstay therapy is phlebotomy, although iron chelation can be used in some patients."
      explanation: Primer supports chelation as an alternative means of treating systemic iron overload in selected patients.
  evidence:
  - reference: PMID:19727383
    reference_title: "The treatment of secondary hemochromatosis."
    supports: PARTIAL
    snippet: "Because secondary hemochromatosis is due to hereditary or acquired anemia, phlebotomy is not a suitable means of removing excess iron in this situation. Rather, the treatment is based on the targeted elimination of iron by means of iron chelators."
    explanation: Secondary hemochromatosis requires chelation when phlebotomy is not feasible.
  - reference: PMID:29620054
    reference_title: "Haemochromatosis."
    supports: SUPPORT
    snippet: "The mainstay therapy is phlebotomy, although iron chelation can be used in some patients."
    explanation: Primer notes chelation as an alternative for selected patients.
  treatment_term:
    preferred_term: iron chelation therapy
    term:
      id: MAXO:0001223
      label: chelator agent therapy
- name: Dietary Modification
  description: >
    Avoiding iron supplements, limiting vitamin C intake (which enhances iron
    absorption), and reducing alcohol consumption to protect the liver.
  target_mechanisms:
  - target: Systemic Iron Overload
    treatment_effect: MODULATES
    description: Dietary and alcohol changes can reduce iron loading pressure and improve iron indices.
    evidence:
    - reference: PMID:38361672
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "This patient was counseled on lifestyle modifications which included abstaining from alcohol and reducing iron and vitamin C intake. As a result, his iron panel parameters improved."
      explanation: Case report shows lifestyle changes improving iron panel parameters.
  evidence:
  - reference: PMID:38361672
    reference_title: "Alcohol Use Unmasking Heterozygous Hereditary Hemochromatosis."
    supports: PARTIAL
    snippet: "This patient was counseled on lifestyle modifications which included abstaining from alcohol and reducing iron and vitamin C intake. As a result, his iron panel parameters improved."
    explanation: Lifestyle changes in alcohol and dietary iron/Vitamin C improved iron indices.
  treatment_term:
    preferred_term: dietary intervention
    term:
      id: MAXO:0000088
      label: dietary intervention
- name: Screening of Family Members
  description: >
    Genetic testing of first-degree relatives is recommended given the autosomal
    recessive inheritance pattern and the benefits of early intervention.
  target_mechanisms:
  - target: Systemic Iron Overload
    treatment_effect: MODULATES
    description: Family screening enables early diagnosis and treatment before systemic iron overload causes irreversible complications.
    evidence:
    - reference: PMID:37121243
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."
      explanation: Early genetic testing in at-risk relatives supports prevention through earlier iron-depletion therapy.
  evidence:
  - reference: PMID:37121243
    reference_title: "Haemochromatosis."
    supports: PARTIAL
    snippet: "Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death."
    explanation: Emphasizes early genetic testing to enable preventive treatment.
  treatment_term:
    preferred_term: genetic counseling
    term:
      id: MAXO:0000079
      label: genetic counseling
differential_diagnoses:
- name: Secondary/Transfusional Iron Overload
  description: >
    Iron accumulation from chronic transfusions or ineffective erythropoiesis can mimic hereditary hemochromatosis but occurs in anemic patients where phlebotomy is not feasible.
  distinguishing_features:
  - History of chronic transfusions or underlying anemia (e.g., thalassemia, MDS)
  - Phlebotomy contraindicated due to anemia; chelation preferred
  - Iron loading often involves reticuloendothelial system in addition to parenchyma
  evidence:
  - reference: PMID:19727383
    reference_title: "The treatment of secondary hemochromatosis."
    supports: SUPPORT
    snippet: "Because secondary hemochromatosis is due to hereditary or acquired anemia, phlebotomy is not a suitable means of removing excess iron in this situation. Rather, the treatment is based on the targeted elimination of iron by means of iron chelators."
    explanation: Highlights anemia/transfusion-related iron overload where chelation is required instead of phlebotomy.
- name: Ferroportin Disease (SLC40A1-Related Hemochromatosis)
  description: >
    Autosomal dominant iron overload from gain-of-function SLC40A1 variants can present with high ferritin and iron deposition, necessitating distinction from HFE-hemochromatosis.
  distinguishing_features:
  - Often autosomal dominant inheritance pattern
  - Elevated ferritin with variable transferrin saturation; iron may accumulate in macrophages and liver
  - Genetic testing reveals SLC40A1 variants affecting ferroportin
  evidence:
  - reference: PMID:38886778
    reference_title: "SLC40A1-related hemochromatosis associated with a p.Y333H mutation in mainland China: a pedigree report and literature review."
    supports: SUPPORT
    snippet: "SLC40A1-related haemochromatosis is associated with gain-of-function mutations in the SLC40A1 gene, which encodes ferroportin."
    explanation: Establishes ferroportin-associated iron overload as a distinct entity to differentiate.
biochemical:
- name: Elevated Transferrin Saturation
  presence: elevated
  biomarker_term:
    preferred_term: transferrin saturation measurement
    term:
      id: NCIT:C98792
      label: Transferrin Saturation Measurement
  notes: >-
    Transferrin saturation (TSAT) above 45-50% is the diagnostic hallmark of
    hemochromatosis, reflecting excess circulating iron and formation of
    non-transferrin-bound iron species.
  readouts:
  - target: Systemic Iron Overload
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: Elevated transferrin saturation reports hepcidin-insufficient iron hyperabsorption and expansion of the plasma iron pool.
    evidence:
    - reference: PMID:39644049
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "iron hyperabsorption, and expansion of the plasma iron pool with increased transferrin saturation, the diagnostic hallmark of the disease"
      explanation: Review explicitly ties increased transferrin saturation to plasma iron-pool expansion and diagnostic use.
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0012463 | Elevated transferrin saturation | Very frequent (99-80%)"
    explanation: Orphanet lists elevated transferrin saturation as very frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:39644049
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "iron hyperabsorption, and expansion of the plasma iron pool with increased transferrin saturation, the diagnostic hallmark of the disease"
    explanation: Recent review confirms elevated TSAT as the diagnostic hallmark of hemochromatosis.
  - reference: PMID:35662478
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Haemochromatosis is characterised by elevated transferrin saturation (TSAT) and progressive iron loading that mainly affects the liver."
    explanation: EASL guidelines define hemochromatosis by elevated TSAT.
- name: Increased Circulating Ferritin
  presence: elevated
  biomarker_term:
    preferred_term: ferritin
    term:
      id: NCIT:C16577
      label: Ferritin
  notes: >-
    Elevated serum ferritin reflects increased total body iron stores.
    Ferritin above 200 ug/L in women or 300 ug/L in men with elevated TSAT
    suggests iron overload. Ferritin above 1000 ug/L increases cirrhosis risk.
  readouts:
  - target: Systemic Iron Overload
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: Elevated ferritin reflects increased iron stores accompanying systemic iron overload.
    evidence:
    - reference: PMID:23985001
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "This can result in elevated serum ferritin, iron deposition in various organs and ultimately end-organ damage"
      explanation: Elevated ferritin accompanies organ iron deposition and end-organ damage in hereditary hemochromatosis.
  - target: Hepatic Iron Toxicity
    relationship: PREDICTS
    direction: POSITIVE
    endpoint_context: PROGNOSTIC
    interpretation: Very high ferritin marks increased risk of cirrhosis and mortality in C282Y homozygotes.
    evidence:
    - reference: PMID:23985001
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "is associated with an increased risk of cirrhosis and mortality in C282Y homozygotes"
      explanation: The review links high serum ferritin with cirrhosis and mortality risk.
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HP:0003281 | Increased circulating ferritin concentration | Very frequent (99-80%)"
    explanation: Orphanet lists increased ferritin as very frequent in symptomatic HFE hemochromatosis.
  - reference: PMID:23985001
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This can result in elevated serum ferritin, iron deposition in various organs and ultimately end-organ damage"
    explanation: Elevated serum ferritin accompanies iron deposition in hereditary hemochromatosis.
  - reference: PMID:35662478
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "TSAT >45% and ferritin >200 μg/L in females and TSAT >50% and ferritin >300 μg/L in males and postmenopausal women"
    explanation: EASL guidelines specify sex-stratified ferritin thresholds for diagnosis.
genetic:
- name: HFE Mutations
  association: Causative
  gene_term:
    preferred_term: HFE
    term:
      id: hgnc:4886
      label: HFE
  notes: >-
    Most common mutation is C282Y (p.Cys282Tyr) homozygosity, accounting for 80-90%
    of hereditary hemochromatosis cases. H63D (p.His63Asp) compound heterozygosity
    also contributes. Clinical penetrance is incomplete and sex-dependent.
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:23985001
    supports: SUPPORT
    snippet: "most commonly in C282Y homozygous individuals"
    explanation: Review confirms C282Y homozygosity as the most common cause of hereditary hemochromatosis.
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "HFE | homeostatic iron regulator | hgnc:4886 | Disease-causing germline mutation(s) in"
    explanation: Orphanet confirms HFE as the causative gene for symptomatic HFE hemochromatosis.
  - reference: PMID:33259166
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "C282Y gene homozygosity is implicated in 80%-95% of cases of hereditary hemochromatosis."
    explanation: Large cohort study confirms C282Y homozygosity accounts for the majority of HH cases.
  - reference: PMID:38479735
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "33.1% died vs 25.4% without HFE variants (HR 1.29, 95% CI: 1.12 to 1.48, p=4.7×10-4)"
    explanation: UK Biobank demonstrates increased all-cause mortality in male C282Y homozygotes.
- name: BMP6 Mutations
  association: Causative
  gene_term:
    preferred_term: BMP6
    term:
      id: hgnc:1073
      label: BMP6
  notes: >-
    BMP6 mutations can cause hemochromatosis through disruption of hepcidin
    regulation. Human BMP6 propeptide variants have been reported with
    dominant transmission and moderate late-onset iron overload.
  inheritance:
  - name: Autosomal Dominant
  evidence:
  - reference: ORPHA:465508
    supports: SUPPORT
    snippet: "BMP6 | bone morphogenetic protein 6 | hgnc:1073 | Disease-causing germline mutation(s) in"
    explanation: Orphanet lists BMP6 as a disease-causing gene for symptomatic HFE hemochromatosis.
  - reference: PMID:26582087
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We identified 3 heterozygous missense mutations in BMP6 (p.Pro95Ser, p.Leu96Pro, and p.Gln113Glu) in 6 unrelated patients with unexplained iron overload"
    explanation: Human cohort study identified heterozygous BMP6 missense mutations in patients with unexplained iron overload.
  - reference: PMID:26582087
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Family studies indicated dominant transmission."
    explanation: The BMP6 propeptide mutation study reported dominant transmission in family studies.
- name: HJV Mutations
  association: Causative
  gene_term:
    preferred_term: HJV
    term:
      id: hgnc:4887
      label: HJV
  notes: >-
    Biallelic HJV pathogenic variants cause hemochromatosis type 2A, a juvenile
    hemochromatosis subtype with severe early iron overload.
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:35449524
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."
    explanation: Case report and review identifies HJV as the type 2A juvenile hemochromatosis gene.
  - reference: PMID:35449524
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We identified the variant c.309C > G (p.Phe103Leu) in the HJV gene in the homozygous state in the patient."
    explanation: The reported juvenile hemochromatosis case had a homozygous HJV variant.
- name: HAMP Mutations
  association: Causative
  gene_term:
    preferred_term: HAMP
    term:
      id: hgnc:15598
      label: HAMP
  notes: >-
    Biallelic HAMP pathogenic variants cause hemochromatosis type 2B by directly
    disrupting the hepcidin hormone that restrains ferroportin-mediated iron
    export.
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:35449524
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Juvenile hemochromatosis type 2a and 2b is an autosomal recessive disease caused by pathogenic variants in HJV and HAMP genes, respectively."
    explanation: Case report and review identifies HAMP as the type 2B juvenile hemochromatosis gene.
  - reference: PMID:20301349
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "biallelic pathogenic variants in HAMP or HJV identified by molecular genetic testing."
    explanation: GeneReviews establishes biallelic HAMP variants as diagnostic for HAMP-related hemochromatosis.
- name: TFR2 Mutations
  association: Causative
  gene_term:
    preferred_term: TFR2
    term:
      id: hgnc:11762
      label: TFR2
  notes: >-
    Biallelic TFR2 pathogenic variants cause hemochromatosis type 3, typically
    with earlier onset than HFE-related disease and multi-organ iron
    accumulation.
  inheritance:
  - name: Autosomal Recessive
  evidence:
  - reference: PMID:20301523
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of TFR2-HC is established in a proband with biallelic pathogenic variants in TFR2 identified by molecular genetic testing."
    explanation: GeneReviews establishes biallelic TFR2 variants as diagnostic for TFR2-related hemochromatosis.
  - reference: PMID:29620054
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Non-HFE forms of haemochromatosis due to mutations in HAMP, HJV or TFR2 are much rarer."
    explanation: Primer identifies TFR2 among rare non-HFE hemochromatosis genes.
clinical_trials:
- name: NCT04202965
  phase: PHASE_II
  status: COMPLETED
  description: >-
    Open-label study of rusfertide (PTG-300), a hepcidin mimetic peptide,
    in adults with HFE-related hereditary hemochromatosis. Assessed effects
    on transferrin saturation, serum iron, and phlebotomy requirements.
  evidence:
  - reference: clinicaltrials:NCT04202965
    supports: SUPPORT
    snippet: "This study will be conducted at multiple sites and every patient will get treated with PTG-300. The objective of the study is to assess the effect of PTG-300 in treating adult hereditary hemochromatosis patients."
    explanation: Completed Phase 2 trial of hepcidin mimetic targeting the core hepcidin insufficiency pathway in HFE-H.
datasets: []
references:
- reference: PMID:20301613
  title: "HFE-Related Hemochromatosis."
  tags:
  - GeneReviews
  findings: []
- reference: PMID:20301349
  title: "HAMP- and HJV-Related Hemochromatosis."
  tags:
  - GeneReviews
  findings: []
- reference: PMID:20301523
  title: "TFR2-Related Hemochromatosis."
  tags:
  - GeneReviews
  findings: []

📚

References & Deep Research

References

PMID:20301613

HFE-Related Hemochromatosis.

No top-level findings curated for this source.

PMID:20301349

HAMP- and HJV-Related Hemochromatosis.

No top-level findings curated for this source.

PMID:20301523

TFR2-Related Hemochromatosis.

No top-level findings curated for this source.

Deep Research

Falcon ▸

Disease Characteristics Research Template

Edison Scientific Literature 26 citations 2026-04-30T13:42:53.892011

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

Disease Name: Hemochromatosis
MONDO ID: (if available)
Category: Mendelian

Research Objectives

Please provide a comprehensive research report on Hemochromatosis covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

What is the disease? Provide a concise overview.
What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
What are the common synonyms and alternative names?
Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
Risk Factors:

Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases
Genetic risk factors (causal variants, susceptibility loci, modifier genes)
Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
Protective Factors:

Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases
Genetic protective factors (protective variants, modifier alleles)
Environmental protective factors (diet, lifestyle, exposures that reduce risk)
Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene
Pathogenic Variants:
Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
Variant type/class (missense, frameshift, nonsense, splice-site, structural)
Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
Functional consequences (loss of function, gain of function, dominant negative)
Modifier Genes: Genes that modify disease severity or expression
Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases
Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

Search first: CDC databases, WHO, PubMed, NHANES
Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc
Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

Search first: Gene Ontology (GO), Reactome, KEGG, PubMed
Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold
Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA
Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

Search first: ImmPort, Immunome Database, IEDB, Gene Ontology
Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

Search first: PubMed, Gene Ontology, Reactome
Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

Search first: BRENDA, UniProt, KEGG, OMIM, PubMed
Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Molecular Profiling (if available):
Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
Advanced Technologies (if applicable):
Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

Organ Level:
Primary organs directly affected
Secondary organ involvement (complications, secondary effects)
Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT
Tissue and Cell Level:
Specific tissue types affected (epithelial, connective, muscle, nervous)
Specific cell populations targeted (with Cell Ontology terms)

Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB
Subcellular Level:
Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas
Localization:
Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

Onset:
Typical age of onset (congenital, pediatric, adult, geriatric)
Onset pattern (acute, subacute, chronic, insidious)

Search first: OMIM, Orphanet, HPO, PubMed
Progression:
Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
Progression rate (rapid, slow, variable)
Disease course pattern (episodic, relapsing-remitting, progressive, stable)
Disease duration (self-limited, chronic lifelong)

Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM
Patterns:
Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

Epidemiology:
Prevalence (cases per 100,000 at given time)
Incidence (new cases per 100,000 per year)

Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries
For Genetic Etiology:
Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
Population Demographics:
Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
Geographic distribution of specific variants
Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

Clinical Tests:
Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
Genetic Testing:

Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen
Overview of recommended genetic testing approach
Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
FISH > Search first: ClinVar, cytogenetics databases, PubMed
Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
Omics-Based Diagnostics (if applicable):
RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
Clinical Criteria:
Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
Screening:
Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

Survival and Mortality:
Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
Morbidity and Function:
Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
Disease Course:
Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
Prediction:
Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

Pharmacotherapy:
Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
Advanced Therapeutics:
Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
Surgical and Interventional:
Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
Supportive and Rehabilitative:
Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
Experimental:
Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
Treatment Outcomes:
Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
Treatment Strategy:
Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

Prevention Levels:
Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
Immunization: Vaccine strategies (if applicable)

Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database
Screening and Early Detection:
Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
Behavioral Interventions: Lifestyle modifications to reduce risk

Search first: CDC, WHO, behavioral intervention databases, Cochrane Library
Counseling: Genetic counseling (risk assessment, family planning guidance)

Search first: NSGC resources, ACMG guidelines, GeneReviews
Public Health:
Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
Prophylaxis: Preventive medications or procedures

Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

Taxonomy: Species affected (with NCBI Taxon identifiers)

Search first: NCBI Taxonomy
Breed: Specific breeds affected (with VBO identifiers if applicable)

Search first: VBO (Vertebrate Breed Ontology)
Gene: Orthologous genes in other species (with NCBI Gene IDs)

Search first: NCBI Gene
Natural Disease:
Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
Comparative Biology:
Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
Transmission (if applicable):
Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

Model Types:
Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
Genetic Models:
Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
Model Characteristics:
Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
Applications:
Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
Resources:
Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

Cite primary literature (PMID preferred) for all mechanistic and clinical claims
Prioritize recent reviews and landmark papers
Include direct quotes from abstracts where possible to support key statements
Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Hemochromatosis (Hereditary Hemochromatosis; HH) — Comprehensive Disease Characteristics Report (2024–2026 evidence emphasis)

Executive summary

Hemochromatosis refers to a group of inherited iron-overload disorders in which insufficient hepcidin activity (or resistance to hepcidin) causes inappropriately increased intestinal iron absorption, elevated transferrin saturation (TSAT), generation of toxic non–transferrin-bound iron, and progressive iron deposition in multiple organs. The most common form is HFE-related hereditary hemochromatosis (classically HFE p.Cys282Tyr (C282Y) homozygosity), which is common in Northern European ancestry but has variable/low clinical penetrance; non‑HFE forms are rarer but often more penetrant and may present earlier with severe complications. Standard care is iron removal by phlebotomy with guideline-based ferritin targets; new pharmacologic approaches aim to replace/augment hepcidin signaling or inhibit ferroportin, potentially reducing phlebotomy burden. (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4, szczerbinska2024hemochromatosis—hownotto pages 8-10)

1. Disease information

1.1 Definition and overview

Disease concept: HH is a genetic iron overload syndrome characterized by hepcidin insufficiency (or hepcidin resistance) with normal erythropoiesis, leading to iron hyperabsorption, increased TSAT (diagnostic hallmark), formation of non–transferrin-bound iron, and iron deposition in organs (liver, heart, endocrine glands, joints). (girelli2024diagnosisandmanagement pages 1-2)
Authoritative definition (abstract quote): “The term hemochromatosis refers to a group of genetic disorders characterized by hepcidin insufficiency… iron hyperabsorption… increased transferrin saturation, the diagnostic hallmark of the disease.” (Girelli et al., Hematology 2024; published Dec 2024; https://doi.org/10.1182/hematology.2024000568) (girelli2024diagnosisandmanagement pages 1-2)

1.2 Key identifiers (availability in retrieved sources)

The tool-retrieved corpus for this run did not include OMIM/Orphanet/ICD-10/ICD-11/MeSH pages, so those identifiers cannot be cited from primary source documents here. - MONDO ID: not available from the citable evidence retrieved in this run.

1.3 Synonyms / alternative names

Common names used in contemporary literature include: - Hereditary hemochromatosis (HH), HFE-hemochromatosis (HFE-H), classic hemochromatosis, iron overload disease. (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 1-2)

1.4 Evidence provenance

Evidence summarized here is derived from aggregated disease-level resources (peer-reviewed reviews/guideline syntheses) and large population cohorts (UK Biobank), plus clinical trial registry records; it is not derived from individual EHR case reports except where cohort outcomes were ascertained from routine care data linkages. (lucas2024hfegenotypeshaemochromatosis pages 4-5, NCT04202965 chunk 1)

2. Etiology

2.1 Primary causal factors

Genetic:
HFE-related HH most commonly due to HFE p.Cys282Tyr (C282Y) homozygosity. (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hereditaryhemochromatosis–hownot pages 8-9)
Non‑HFE HH includes defects in hepcidin synthesis/regulation (e.g., HJV, HAMP, TFR2) and hepcidin resistance (e.g., SLC40A1/ferroportin). (szczerbinska2024hemochromatosis—hownotto pages 8-10, girelli2024diagnosisandmanagement pages 2-4)
Mechanistic: dysregulation of the hepcidin–ferroportin axis is central, leading to increased iron export into plasma and increased intestinal absorption. (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 1-2)

2.2 Risk factors (genetic and environmental/lifestyle)

Sex is a major modifier: HFE-H has “low penetrance, particularly in females.” (Girelli et al., Hematology 2024; Dec 2024; https://doi.org/10.1182/hematology.2024000568) (girelli2024diagnosisandmanagement pages 1-2)
Lifestyle/metabolic cofactors modulate clinical expression; HFE-H can be considered “multifactorial” with “genetic and lifestyle cofactors (especially alcohol and dysmetabolic features)” influencing phenotypic expression. (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4)

2.3 Protective factors

A commonly cited physiologic protection in females is iron loss through menstruation/pregnancy; contemporary reviews emphasize lower penetrance in females, consistent with this biological mechanism. (girelli2024diagnosisandmanagement pages 1-2)

2.4 Gene–environment interactions

HFE-H is explicitly described as resembling a multifactorial condition because environmental and metabolic factors (e.g., alcohol, coexisting metabolic liver disease) interact with HFE genotype to determine penetrance and severity. (girelli2024diagnosisandmanagement pages 2-4)

3. Phenotypes (clinical features) and HPO mappings

3.1 Core phenotype spectrum (disease-level)

HH can cause multisystem iron deposition with manifestations in: - Liver: iron overload, fibrosis/cirrhosis, hepatocellular carcinoma (HCC) risk in advanced fibrosis/cirrhosis. (girelli2024diagnosisandmanagement pages 2-4, marcon2024tsaturatedinsightsclarifying pages 16-17) - Musculoskeletal: arthropathy and increased joint replacement incidence in p.C282Y homozygotes in community cohorts. (lucas2024hfegenotypeshaemochromatosis pages 4-5, lucas2024hfegenotypeshaemochromatosis pages 7-7) - Endocrine/metabolic: diabetes risk increased in male p.C282Y homozygotes in UK Biobank outcomes. (lucas2024hfegenotypeshaemochromatosis pages 6-7) - Neurologic (association signals): delirium/dementia/Parkinson’s disease associations reported in UK Biobank analyses (interpretation cautious due to multiple-testing). (lucas2024hfegenotypeshaemochromatosis pages 6-7)

3.2 Phenotype timing and progression

Typical onset: adult-onset is typical for HFE-H; non-HFE forms can present earlier and more severely (e.g., juvenile forms). (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10)

3.3 Quantitative phenotype frequencies / statistics (UK Biobank; BMJ Open 2024)

From a large prospective cohort with outcomes to age 80: - Male p.C282Y homozygotes: cumulative incidence of diagnosed hemochromatosis ~56.4% by age 80, and higher all-cause mortality (HR 1.29; 95% CI 1.12–1.48) with cumulative death incidence 33.1% vs 25.4% in those without HFE variants. (Lucas et al., BMJ Open; published Mar 2024; https://doi.org/10.1136/bmjopen-2023-081926) (lucas2024hfegenotypeshaemochromatosis pages 4-5) - Women p.C282Y homozygotes: cumulative incidence of diagnosed hemochromatosis 40.5% by age 80. (lucas2024hfegenotypeshaemochromatosis pages 6-7) - Genotypes with low penetrance: p.C282Y/p.H63D and p.H63D+/+ showed low diagnosis cumulative incidences (~5.4% in men and ~2.7% in women for compound heterozygotes; ~1.9% for H63D homozygosity). (lucas2024hfegenotypeshaemochromatosis pages 7-7)

3.4 Suggested HPO terms (examples)

(These are ontology mapping suggestions for knowledge base normalization.) - Elevated transferrin saturation: HP:0012467 (Abnormal iron saturation) (map conceptually to TSAT elevation) (supported conceptually by TSAT as hallmark) (girelli2024diagnosisandmanagement pages 1-2) - Hyperferritinemia: HP:0003281 (supported by diagnostic role of ferritin) (girelli2024diagnosisandmanagement pages 2-4) - Hepatic iron overload: HP:0003280 (supported by MRI/LIC role and hepatic deposition) (szczerbinska2024hemochromatosis—hownotto pages 8-10) - Liver fibrosis/cirrhosis: HP:0001395 (supported by increased fibrosis/cirrhosis risk) (lucas2024hfegenotypeshaemochromatosis pages 6-7) - Diabetes mellitus: HP:0000819 (supported by increased diabetes incidence in male p.C282Y homozygotes) (lucas2024hfegenotypeshaemochromatosis pages 6-7) - Arthropathy / joint disease: HP:0002829 (supported by increased joint replacement risk) (lucas2024hfegenotypeshaemochromatosis pages 4-5) - Fatigue: HP:0012378 (supported by baseline fatigue signal in older male homozygotes) (lucas2024hfegenotypeshaemochromatosis pages 4-5)

3.5 Quality of life impact

Direct QoL instrument data (e.g., SF-36/EQ-5D) were not retrieved in the citable evidence set for this run; however, symptoms such as fatigue and joint disease are plausibly QoL-limiting, and fatigue associations were directly quantified in UK Biobank (baseline OR in older men). (lucas2024hfegenotypeshaemochromatosis pages 4-5)

4. Genetic / molecular information

4.1 Causal genes (major)

HFE (type 1, classic), HJV, HAMP, TFR2, SLC40A1 (non-HFE forms including juvenile hemochromatosis and ferroportin disease spectrum). (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10, girelli2024diagnosisandmanagement pages 2-4)

4.2 Key pathogenic variants and genotype interpretation

HFE-H is strongly linked to HFE p.Cys282Tyr (C282Y) homozygosity, which is common in Northern European ancestry but has variable clinical penetrance. (girelli2024diagnosisandmanagement pages 1-2)
BIOIRON-aligned interpretation emphasizes C282Y homozygosity as the pathogenic HFE genotype for HFE-related HH, with substantial debate/variation in how other HFE genotypes should be managed. (marcon2024tsaturatedinsightsclarifying pages 1-2, marcon2024tsaturatedinsightsclarifying pages 16-17)

4.3 Modifier genetics (polygenic effects)

A recent UK Biobank analysis (preprint) suggests a polygenic score for TSAT modifies clinical penetrance among C282Y homozygotes, with higher genetically predicted TSAT increasing clinical outcome incidence; this requires peer-reviewed validation. (lucas2025geneticandlifestyle pages 12-15)

4.4 Functional consequences (current understanding)

Across HH types, the shared physiological consequence is inappropriately low hepcidin effect relative to body iron, leading to increased plasma iron and tissue deposition. (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4)

4.5 Epigenetics / chromosomal abnormalities

No epigenetic or chromosomal-abnormality evidence specific to HH was retrieved in the citable set for this run.

5. Mechanism / pathophysiology

5.1 Causal chain (high-level)

1) Genetic defect (HFE or non-HFE hepcidin pathway genes) → 2) Hepcidin insufficiency or resistance → 3) Increased ferroportin-mediated iron export + increased intestinal iron absorption → 4) High TSAT and non–transferrin-bound iron formation → 5) Parenchymal iron deposition (liver, heart, endocrine glands, joints) → 6) Oxidative injury and organ dysfunction. (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 1-2)

5.2 Pathways and processes (ontology suggestions)

Key pathway: hepcidin–ferroportin axis / systemic iron homeostasis. (girelli2024diagnosisandmanagement pages 1-2)
Suggested GO biological process terms:
Iron ion homeostasis (GO:0055072)
Cellular iron ion homeostasis (GO:0006879)
Regulation of hepcidin production (conceptual mapping; hepcidin insufficiency is central) (girelli2024diagnosisandmanagement pages 1-2)
Suggested cell types (Cell Ontology, CL) implicated by organ deposition and regulation discussions:
Hepatocyte (CL:0000182) (hepcidin production context) (girelli2024diagnosisandmanagement pages 1-2)
Macrophage / Kupffer cell (CL:0000235 / liver macrophage) (iron handling in liver; discussed as important in regulation frameworks) (girelli2024diagnosisandmanagement pages 2-4)
Enterocyte (CL:0000584) (intestinal absorption) (szczerbinska2024hemochromatosis—hownotto pages 1-2)

5.3 Immune/inflammation involvement

While ferritin is noted to be nonspecific and increased in inflammatory states (confounding differential diagnosis), direct immune-pathogenesis evidence was not central in the retrieved set beyond this diagnostic confounding. (girelli2024diagnosisandmanagement pages 2-4)

5.4 Molecular profiling / omics

No transcriptomic/proteomic/metabolomic disease signatures were retrieved as citable evidence in this run.

6. Anatomical structures affected (UBERON suggestions)

Liver (primary): UBERON:0002107 (hepatic iron loading; fibrosis/cirrhosis/HCC surveillance considerations). (girelli2024diagnosisandmanagement pages 2-4, lucas2024hfegenotypeshaemochromatosis pages 6-7)
Heart: UBERON:0000948 (iron deposition cited as part of multisystem accumulation). (girelli2024diagnosisandmanagement pages 1-2)
Endocrine glands/pancreas: UBERON:0001264 (pancreas; diabetes association) (girelli2024diagnosisandmanagement pages 1-2, lucas2024hfegenotypeshaemochromatosis pages 6-7)
Joints/synovium: UBERON:0002206 (synovial joint) (girelli2024diagnosisandmanagement pages 1-2)

Subcellular (GO cellular component suggestions): lysosome (GO:0005764) and mitochondrion (GO:0005739) are plausible sites of iron-related oxidative injury, but specific subcellular localization evidence was not retrieved in the citable set.

7. Inheritance and population

7.1 Inheritance patterns

HFE-H (type 1): typically autosomal recessive. (girelli2024diagnosisandmanagement pages 1-2)
Non-HFE juvenile forms (HJV/HAMP/TFR2): autosomal recessive. (szczerbinska2024hemochromatosis—hownotto pages 8-10, girelli2024diagnosisandmanagement pages 2-4)
Ferroportin-related (SLC40A1): often autosomal dominant with hepcidin resistance phenotypes described. (szczerbinska2024hemochromatosis—hownotto pages 8-10)

7.2 Population frequency and penetrance (recent synthesis)

Prevalence of genetic risk genotype: HFE C282Y homozygosity is described as present in “nearly 1 in 200 people of Northern European descent.” (Girelli et al., Hematology 2024; Dec 2024; https://doi.org/10.1182/hematology.2024000568) (girelli2024diagnosisandmanagement pages 1-2)
Clinical penetrance is variable/low: review syntheses emphasize variable penetrance and diagnostic complexity. (marcon2024tsaturatedinsightsclarifying pages 1-2, girelli2024diagnosisandmanagement pages 1-2)

8. Diagnostics

8.1 Core laboratory hallmarks

TSAT is the “diagnostic hallmark” in HH definitions; thresholds around >45–50% are commonly used to trigger evaluation. (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10)
Ferritin is used to quantify iron burden but is nonspecific and can be elevated in inflammation, cytolysis, or metabolic conditions. (girelli2024diagnosisandmanagement pages 2-4)

8.2 Guideline elements and algorithms (visual evidence from a 2024 guideline synthesis)

The Marcon et al. 2024 review provides comparative tables and an algorithm that summarize guideline differences for diagnosis and phlebotomy targets: - Table comparing diagnostic elements (TSAT/SF cutoffs) across guidelines and Table comparing treatment targets (including induction and maintenance serum ferritin goals). (marcon2024tsaturatedinsightsclarifying media 39ab28d3, marcon2024tsaturatedinsightsclarifying media 7ecf4a95) - Diagnostic/management algorithm (figure) for HFE-related HH and differential diagnosis approach to hyperferritinemia. (marcon2024tsaturatedinsightsclarifying media f71af5e5, marcon2024tsaturatedinsightsclarifying media 8a05bd9e)

8.3 Imaging and biopsy

MRI is highlighted as a reference/essential technique for hepatic iron quantification and staging in contemporary practice; liver biopsy is described as rarely required in modern workups except selected cases. (marcon2024tsaturatedinsightsclarifying pages 16-17, szczerbinska2024hemochromatosis—hownotto pages 8-10)

8.4 Genetic testing strategy

HFE accounts for the vast majority of hereditary cases; genetic testing is described as the “gold standard diagnostic test,” with initial biochemical screening by TSAT and ferritin. (nogueyra2024thegeneticdiagnostics pages 3-4)
If C282Y is absent but iron overload is present, reviews recommend considering gene panels for non‑HFE etiologies after excluding common secondary causes (e.g., metabolic liver disease, alcohol-associated liver disease). (szczerbinska2024hemochromatosis—hownotto pages 8-10, szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11)

8.5 Differential diagnosis (high level)

Hyperferritinemia with normal TSAT is often not HH and may reflect metabolic/inflammatory etiologies; specialist evaluation is recommended in such patterns. (girelli2024diagnosisandmanagement pages 2-4)

9. Outcomes / prognosis

9.1 Prognosis with early treatment

Reviews emphasize that contemporary HFE-H is “mostly diagnosed before organ damage and is easily treated by phlebotomy, with an excellent prognosis.” (Girelli et al., Hematology 2024; Dec 2024; https://doi.org/10.1182/hematology.2024000568) (girelli2024diagnosisandmanagement pages 1-2)

9.2 Morbidity and mortality statistics (UK Biobank)

Male p.C282Y homozygotes showed increased all-cause mortality (HR 1.29; cumulative deaths 33.1% vs 25.4% by age 80) and increased liver/joint/other outcomes. (lucas2024hfegenotypeshaemochromatosis pages 4-5)
These outcome signals were also seen among individuals undiagnosed at baseline, supporting under-recognition in routine care. (lucas2024hfegenotypeshaemochromatosis pages 4-5)

10. Treatment

10.1 Standard-of-care: phlebotomy (venesection)

First-line therapy: repeated therapeutic phlebotomy (venesection), commonly ~450–500 mL per session. (marcon2024tsaturatedinsightsclarifying pages 16-17, szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11)
Example induction/maintenance targets from cited EASL-aligned summaries: ferritin targets often include <50 µg/L during induction and <100 µg/L during maintenance; TSAT is not necessarily a treatment target in some guidelines. (szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11)
A 2024 synthesis includes comparative guideline tables for phlebotomy targets (induction and maintenance) and a diagnostic/treatment algorithm. (marcon2024tsaturatedinsightsclarifying media 39ab28d3, marcon2024tsaturatedinsightsclarifying media 7ecf4a95, marcon2024tsaturatedinsightsclarifying media f71af5e5)

10.2 Blood donation as real-world implementation

After iron depletion, maintenance phlebotomy “can be usefully transformed into a blood donation program,” representing a practical implementation pathway in suitable health systems. (girelli2024diagnosisandmanagement pages 1-2)

10.3 Chelation therapy (selected indications)

Chelation is generally reserved for patients who cannot undergo phlebotomy or are refractory/intolerant, due to toxicity and limited evidence relative to phlebotomy. (nogueyra2024thegeneticdiagnostics pages 3-4, marcon2024tsaturatedinsightsclarifying pages 31-31)

10.4 Emerging / investigational therapies (2023–2026)

Hepcidin mimetic / hepcidin-pathway augmentation

Rusfertide (PTG‑300): ClinicalTrials.gov describes a Phase 2, open-label, single-arm study in adults with HFE-related HH (NCT04202965), completed, with results first posted 2023‑06‑15. Primary endpoints included change in TSAT and serum iron to Week 24, and a key secondary endpoint was change in phlebotomy frequency over 24 weeks pre vs on treatment. (ClinicalTrials.gov; posted results 2023-06-15; https://clinicaltrials.gov/study/NCT04202965) (NCT04202965 chunk 1)

Ferroportin inhibition

Vamifeport: A Phase 2 interventional trial record exists for HFE-related HH (NCT07332091, CSL Behring) with a record version date 2026‑04‑30 and multiple European sites listed as not yet recruiting in the extracted chunk; additional registry chunks are needed for endpoints/dosing. (ClinicalTrials.gov; https://clinicaltrials.gov/study/NCT07332091) (NCT07332091 chunk 4)

10.5 MAXO term suggestions

Therapeutic phlebotomy / venesection: MAXO:0000449 (therapeutic phlebotomy; conceptual mapping)
Iron chelation therapy: MAXO:0000755 (chelation therapy; conceptual mapping)
Genetic counseling/cascade testing: MAXO:0000079 (genetic counseling; conceptual mapping)

11. Prevention

11.1 Secondary prevention: early detection and intervention

The disease evolves over decades and is highly amenable to preventing complications via early recognition and venesection, motivating screening discussions. (delatycki2024populationscreeningfor pages 1-2, girelli2024diagnosisandmanagement pages 1-2)

11.2 Screening strategies (2024 expert analyses)

Population screening (expert argument in favor): Delatycki & Allen (2024) argue HH is a strong candidate for population genetic screening because early intervention is simple and effective, and may expand the blood donor pool; they discuss genotype vs phenotype screening tradeoffs and conclude it is timely to reconsider genotype-based strategies focusing on C282Y. (Delatycki & Allen, Genes; Jul 2024; https://doi.org/10.3390/genes15080967) (delatycki2024populationscreeningfor pages 1-2, delatycki2024populationscreeningfor pages 4-5, delatycki2024populationscreeningfor pages 5-6)
Caution/targeted screening: Another 2024 review emphasizes underdiagnosis but suggests targeted screening (e.g., higher-risk ancestry/sex subgroups) rather than universal screening, partly due to lower-than-expected penetrance. (szczerbinska2024hemochromatosis—hownotto pages 13-14)

11.3 Cascade screening and counseling

Family screening for first-degree relatives is repeatedly recommended/implicit in diagnostic frameworks because of the inherited nature and actionable intervention. (szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11)

12. Other species / natural disease

No veterinary/natural disease evidence (OMIA/VetCompass) was retrieved in the citable set for this run.

13. Model organisms

No model organism-specific primary studies were retrieved in the citable set for this run.

14. Structured summary artifact (genes/types)

The following table summarizes major HH types, genes, inheritance, and mechanistic class.

Hemochromatosis type	Major causal gene(s)	Usual inheritance	Core mechanistic defect	Typical onset / severity	Key notes
Type 1 (classic HFE-related hemochromatosis)	HFE; most commonly p.Cys282Tyr (C282Y) homozygosity	Autosomal recessive	Relative hepcidin deficiency causing increased intestinal iron absorption, increased transferrin saturation, and parenchymal iron loading	Usually adult-onset; common in Northern European ancestry; often low clinical penetrance, especially in females, but strong biochemical penetrance (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4, szczerbinska2024hemochromatosis—hownotto pages 1-2)	Most common form; diagnostic hallmark is elevated TSAT; phlebotomy is standard treatment; BIOIRON classification emphasizes C282Y homozygosity as the pathogenic HFE genotype for HFE-related HH (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hereditaryhemochromatosis–hownot pages 8-9)
Type 2A (juvenile hemochromatosis)	HJV	Autosomal recessive	Severe hepcidin deficiency	Juvenile or early adult onset; typically severe, with early endocrine, hepatic, and cardiac complications (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10, girelli2024diagnosisandmanagement pages 2-4)	Non-HFE form; much rarer but more penetrant than HFE-H; can present with very low/undetectable hepcidin (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4)
Type 2B (juvenile hemochromatosis)	HAMP	Autosomal recessive	Direct hepcidin deficiency due to hepcidin gene defects	Juvenile or early adult onset; typically severe and rapidly progressive (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10, girelli2024diagnosisandmanagement pages 2-4)	Rare non-HFE HH; often grouped with HJV-related juvenile disease because both produce profound hepcidin deficiency (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4)
Type 3	TFR2	Autosomal recessive	Hepcidin deficiency due to impaired iron sensing/signaling	Often adult or earlier-than-HFE onset; can be severe (szczerbinska2024hemochromatosis—hownotto pages 8-10, girelli2024diagnosisandmanagement pages 2-4)	Rare non-HFE HH; included in gene-panel testing when C282Y is absent and iron overload is present after secondary causes are excluded (szczerbinska2024hemochromatosis—hownotto pages 8-10, szczerbinska2024hereditaryhemochromatosis–hownot pages 8-9)
Type 4 / ferroportin disease (non-classic hemochromatosis spectrum)	SLC40A1	Usually autosomal dominant	Either defective ferroportin export phenotype or hepcidin resistance; hemochromatosis phenotype classically linked to hepcidin resistance	Variable; can be adult-onset; severity varies by subtype (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10)	Distinct from classic HFE-H; SLC40A1-related disease may present differently from hepcidin-deficiency states and should be considered in non-HFE evaluation (girelli2024diagnosisandmanagement pages 1-2, szczerbinska2024hemochromatosis—hownotto pages 8-10)
Rare/expanded non-HFE differential within iron-overload workup	Rare HFE variants and broader iron genes in panels (e.g., CP, BMP6, TF, FTL in some diagnostic panels)	Variable	Variable; may affect hepcidin regulation or mimic HH	Variable; depends on gene and context (szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11, szczerbinska2024hemochromatosis—hownotto pages 8-10)	Not all genes in expanded panels define classical hereditary hemochromatosis; testing is generally recommended only after exclusion of common secondary causes and common HFE genotypes (szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11, szczerbinska2024hemochromatosis—hownotto pages 8-10, szczerbinska2024hereditaryhemochromatosis–hownot pages 8-9)

Table: This table summarizes the major hereditary hemochromatosis subtypes, their causal genes, inheritance patterns, core pathophysiology, and typical clinical presentation. It is useful as a compact reference for distinguishing classic HFE-related disease from rarer, often more penetrant non-HFE forms.

15. Notes on evidence gaps in this run

Ontology identifiers (OMIM, Orphanet, ICD-10/11, MeSH, MONDO) were not retrievable as citable sources in this run; a follow-up retrieval targeting those databases would be required to populate identifiers with citations.
Detailed omics, epigenetic findings, animal models, and QoL instrument-based outcomes were not retrieved in the citable evidence set for this run.

Key recent sources (with URLs and publication dates)

Girelli D, Marchi G, Busti F. Diagnosis and management of hereditary hemochromatosis: lifestyle modification, phlebotomy, and blood donation. Hematology. Dec 2024. https://doi.org/10.1182/hematology.2024000568 (girelli2024diagnosisandmanagement pages 1-2, girelli2024diagnosisandmanagement pages 2-4)
Lucas MR et al. HFE genotypes, haemochromatosis diagnosis and clinical outcomes at age 80 years: a prospective cohort study in the UK Biobank. BMJ Open. Mar 2024. https://doi.org/10.1136/bmjopen-2023-081926 (lucas2024hfegenotypeshaemochromatosis pages 4-5)
Marcon C et al. TSAT-Urated Insights: Clarifying the Complexities of Hereditary Hemochromatosis and Its Guidelines. Hemato. Dec 2024. https://doi.org/10.3390/hemato5040035 (marcon2024tsaturatedinsightsclarifying pages 16-17, marcon2024tsaturatedinsightsclarifying media 39ab28d3, marcon2024tsaturatedinsightsclarifying media 7ecf4a95, marcon2024tsaturatedinsightsclarifying media f71af5e5, marcon2024tsaturatedinsightsclarifying media 8a05bd9e, marcon2024tsaturatedinsightsclarifying pages 1-2)
Delatycki MB, Allen KJ. Population Screening for Hereditary Haemochromatosis—Should It Be Carried Out, and If So, How? Genes. Jul 2024. https://doi.org/10.3390/genes15080967 (delatycki2024populationscreeningfor pages 1-2, delatycki2024populationscreeningfor pages 4-5)
ClinicalTrials.gov. NCT04202965 (rusfertide/PTG‑300), results first posted 2023‑06‑15. https://clinicaltrials.gov/study/NCT04202965 (NCT04202965 chunk 1)
ClinicalTrials.gov. NCT07332091 (vamifeport), record version 2026‑04‑30. https://clinicaltrials.gov/study/NCT07332091 (NCT07332091 chunk 4)

References

(girelli2024diagnosisandmanagement pages 1-2): Domenico Girelli, Giacomo Marchi, and Fabiana Busti. Diagnosis and management of hereditary hemochromatosis: lifestyle modification, phlebotomy, and blood donation. Hematology, 2024:434-442, Dec 2024. URL: https://doi.org/10.1182/hematology.2024000568, doi:10.1182/hematology.2024000568. This article has 22 citations and is from a peer-reviewed journal.
(girelli2024diagnosisandmanagement pages 2-4): Domenico Girelli, Giacomo Marchi, and Fabiana Busti. Diagnosis and management of hereditary hemochromatosis: lifestyle modification, phlebotomy, and blood donation. Hematology, 2024:434-442, Dec 2024. URL: https://doi.org/10.1182/hematology.2024000568, doi:10.1182/hematology.2024000568. This article has 22 citations and is from a peer-reviewed journal.
(szczerbinska2024hemochromatosis—hownotto pages 8-10): Agnieszka Szczerbinska, Beata Kasztelan-Szczerbinska, Anna Rycyk-Bojarzynska, Janusz Kocki, and Halina Cichoz-Lach. Hemochromatosis—how not to overlook and properly manage “iron people”—a review. Journal of Clinical Medicine, 13:3660, Jun 2024. URL: https://doi.org/10.3390/jcm13133660, doi:10.3390/jcm13133660. This article has 14 citations.
(szczerbinska2024hemochromatosis—hownotto pages 1-2): Agnieszka Szczerbinska, Beata Kasztelan-Szczerbinska, Anna Rycyk-Bojarzynska, Janusz Kocki, and Halina Cichoz-Lach. Hemochromatosis—how not to overlook and properly manage “iron people”—a review. Journal of Clinical Medicine, 13:3660, Jun 2024. URL: https://doi.org/10.3390/jcm13133660, doi:10.3390/jcm13133660. This article has 14 citations.
(lucas2024hfegenotypeshaemochromatosis pages 4-5): Mitchell R Lucas, Janice L Atkins, Luke C Pilling, Jeremy D Shearman, and David Melzer. Hfe genotypes, haemochromatosis diagnosis and clinical outcomes at age 80 years: a prospective cohort study in the uk biobank. BMJ Open, 14:e081926, Mar 2024. URL: https://doi.org/10.1136/bmjopen-2023-081926, doi:10.1136/bmjopen-2023-081926. This article has 42 citations and is from a peer-reviewed journal.
(NCT04202965 chunk 1): PTG-300 in Subjects With Hereditary Hemochromatosis. Protagonist Therapeutics, Inc.. 2020. ClinicalTrials.gov Identifier: NCT04202965
(szczerbinska2024hereditaryhemochromatosis–hownot pages 8-9): A Szczerbinska and B Kasztelan-Szczerbinska. Hereditary hemochromatosis–how not to overlook and properly manage “iron people”-a critical overview. Unknown journal, 2024.
(marcon2024tsaturatedinsightsclarifying pages 16-17): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(lucas2024hfegenotypeshaemochromatosis pages 7-7): Mitchell R Lucas, Janice L Atkins, Luke C Pilling, Jeremy D Shearman, and David Melzer. Hfe genotypes, haemochromatosis diagnosis and clinical outcomes at age 80 years: a prospective cohort study in the uk biobank. BMJ Open, 14:e081926, Mar 2024. URL: https://doi.org/10.1136/bmjopen-2023-081926, doi:10.1136/bmjopen-2023-081926. This article has 42 citations and is from a peer-reviewed journal.
(lucas2024hfegenotypeshaemochromatosis pages 6-7): Mitchell R Lucas, Janice L Atkins, Luke C Pilling, Jeremy D Shearman, and David Melzer. Hfe genotypes, haemochromatosis diagnosis and clinical outcomes at age 80 years: a prospective cohort study in the uk biobank. BMJ Open, 14:e081926, Mar 2024. URL: https://doi.org/10.1136/bmjopen-2023-081926, doi:10.1136/bmjopen-2023-081926. This article has 42 citations and is from a peer-reviewed journal.
(marcon2024tsaturatedinsightsclarifying pages 1-2): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(lucas2025geneticandlifestyle pages 12-15): Mitchell R Lucas, João Delgado, Robin N Beaumont, Gareth Hawkes, Andrew R Wood, Caroline F Wright, Jeremy Shearman, Janice L Atkins, and Luke C Pilling. Genetic and lifestyle modifiers of haemochromatosis-related clinical outcomes in hfe c282y homozygotes: prospective cohort study in uk biobank. MedRxiv, Aug 2025. URL: https://doi.org/10.1101/2025.08.22.25334187, doi:10.1101/2025.08.22.25334187. This article has 0 citations.
(marcon2024tsaturatedinsightsclarifying media 39ab28d3): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(marcon2024tsaturatedinsightsclarifying media 7ecf4a95): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(marcon2024tsaturatedinsightsclarifying media f71af5e5): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(marcon2024tsaturatedinsightsclarifying media 8a05bd9e): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(nogueyra2024thegeneticdiagnostics pages 3-4): Sol Villa Nogueyra, María F Trujillo Rodríguez, María L Garcia Oliva, Andrea Vidal-Gallardo, Amanda Ramírez Leal, Jose Beltran Hernandez, Andres Manuel Vargas Beltran, José D Guillen Sandoval, David Arriaga Escamilla, and Marily Martinez Ramirez. The genetic diagnostics of hemochromatosis: disparities in low- versus high-income countries. Cureus, Jul 2024. URL: https://doi.org/10.7759/cureus.64074, doi:10.7759/cureus.64074. This article has 3 citations.
(szczerbinska2024hereditaryhemochromatosis–hownot pages 9-11): A Szczerbinska and B Kasztelan-Szczerbinska. Hereditary hemochromatosis–how not to overlook and properly manage “iron people”-a critical overview. Unknown journal, 2024.
(marcon2024tsaturatedinsightsclarifying pages 31-31): Chiara Marcon, Marta Medeot, Alessio Michelazzi, Valentina Simeon, Alessandra Poz, Sara Cmet, Elisabetta Fontanini, Anna Rosa Cussigh, Marianna Chiozzotto, and Giovanni Barillari. Tsat-urated insights: clarifying the complexities of hereditary hemochromatosis and its guidelines. Hemato, 5:459-489, Dec 2024. URL: https://doi.org/10.3390/hemato5040035, doi:10.3390/hemato5040035. This article has 2 citations.
(NCT07332091 chunk 4): Efficacy and Safety of Vamifeport in Adult Participants With Homeostatic Iron Regulator Gene (HFE)-Related Hereditary Hemochromatosis. CSL Behring. 2026. ClinicalTrials.gov Identifier: NCT07332091
(delatycki2024populationscreeningfor pages 1-2): Martin B. Delatycki and Katrina J. Allen. Population screening for hereditary haemochromatosis—should it be carried out, and if so, how? Genes, 15:967, Jul 2024. URL: https://doi.org/10.3390/genes15080967, doi:10.3390/genes15080967. This article has 5 citations.
(delatycki2024populationscreeningfor pages 4-5): Martin B. Delatycki and Katrina J. Allen. Population screening for hereditary haemochromatosis—should it be carried out, and if so, how? Genes, 15:967, Jul 2024. URL: https://doi.org/10.3390/genes15080967, doi:10.3390/genes15080967. This article has 5 citations.
(delatycki2024populationscreeningfor pages 5-6): Martin B. Delatycki and Katrina J. Allen. Population screening for hereditary haemochromatosis—should it be carried out, and if so, how? Genes, 15:967, Jul 2024. URL: https://doi.org/10.3390/genes15080967, doi:10.3390/genes15080967. This article has 5 citations.
(szczerbinska2024hemochromatosis—hownotto pages 13-14): Agnieszka Szczerbinska, Beata Kasztelan-Szczerbinska, Anna Rycyk-Bojarzynska, Janusz Kocki, and Halina Cichoz-Lach. Hemochromatosis—how not to overlook and properly manage “iron people”—a review. Journal of Clinical Medicine, 13:3660, Jun 2024. URL: https://doi.org/10.3390/jcm13133660, doi:10.3390/jcm13133660. This article has 14 citations.

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Inheritance

Subtypes

Pathophysiology

Pathograph

Phenotypes

Genetic Associations

Treatments

Biochemical Markers

Differential Diagnoses

Clinical Trials

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References & Deep Research

References

Deep Research

Disease Characteristics Research Template

Target Disease

Research Objectives

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome/Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Citation Requirements

Output Format

Hemochromatosis (Hereditary Hemochromatosis; HH) — Comprehensive Disease Characteristics Report (2024–2026 evidence emphasis)

Executive summary

1. Disease information

1.1 Definition and overview

1.2 Key identifiers (availability in retrieved sources)

1.3 Synonyms / alternative names

1.4 Evidence provenance

2. Etiology

2.1 Primary causal factors

2.2 Risk factors (genetic and environmental/lifestyle)

2.3 Protective factors

2.4 Gene–environment interactions

3. Phenotypes (clinical features) and HPO mappings

3.1 Core phenotype spectrum (disease-level)

3.2 Phenotype timing and progression

3.3 Quantitative phenotype frequencies / statistics (UK Biobank; BMJ Open 2024)

3.4 Suggested HPO terms (examples)

3.5 Quality of life impact

4. Genetic / molecular information

4.1 Causal genes (major)

4.2 Key pathogenic variants and genotype interpretation

4.3 Modifier genetics (polygenic effects)

4.4 Functional consequences (current understanding)

4.5 Epigenetics / chromosomal abnormalities

5. Mechanism / pathophysiology

5.1 Causal chain (high-level)

5.2 Pathways and processes (ontology suggestions)

5.3 Immune/inflammation involvement

5.4 Molecular profiling / omics

6. Anatomical structures affected (UBERON suggestions)

7. Inheritance and population

7.1 Inheritance patterns

7.2 Population frequency and penetrance (recent synthesis)

8. Diagnostics

8.1 Core laboratory hallmarks

8.2 Guideline elements and algorithms (visual evidence from a 2024 guideline synthesis)

8.3 Imaging and biopsy

8.4 Genetic testing strategy

8.5 Differential diagnosis (high level)

9. Outcomes / prognosis

9.1 Prognosis with early treatment

9.2 Morbidity and mortality statistics (UK Biobank)

10. Treatment

10.1 Standard-of-care: phlebotomy (venesection)