BASICS
Description
- Genetic disorder causing iron overload from increased intestinal absorption.
- Surplus iron deposits in tissues including liver, pancreas, heart β organ damage.
- Patients often asymptomatic initially; late complications include diabetes, cirrhosis, skin pigmentation, cardiac issues.
Epidemiology
- Clinical symptoms usually present in 3rdβ5th decades for types 1, 3, 4; juvenile type 2 presents earlier.
- More common clinical expression in men due to menstruation delaying onset in women.
- Prevalence: ~5.4% carry C282Y mutation; homozygosity ~0.3% in US; type 1 accounts for >90% cases in US, mostly northern European descent.
ETIOLOGY AND PATHOPHYSIOLOGY
- Genetic mutations:
- Type 1: HFE gene (C282Y, H63D mutations) - most common
- Type 2 (juvenile): HJV or HAMP genes
- Type 3: TFR2 gene
- Type 4: SLC11A3 gene (ferroportin disease)
- Types 1β3 cause hepcidin deficiency β increased ferroportin activity β excessive iron absorption.
- Type 4 involves ferroportin insensitivity or inactivity, causing iron accumulation in mesenchymal tissues.
- Excess unbound plasma iron deposits in organs, leading to dysfunction.
Genetics
- Autosomal recessive inheritance (types 1β3); type 4 is autosomal dominant.
- Variable expressivity and incomplete penetrance.
- ~75% men and 50% women with type 1 have increased transferrin saturation.
RISK FACTORS
- Positive family history
- Male sex (30β50 years typical onset)
- Alcohol use (increases iron absorption and liver damage)
- Menstruation and pregnancy delay symptoms in women.
PREVENTION
- Screen first-degree relatives with fasting transferrin saturation and ferritin.
- Genetic testing recommended for children of diagnosed parents.
- Population screening not recommended due to low penetrance.
DIAGNOSIS
History
- Fatigue, weakness
- Arthralgia
- Abdominal pain
- Loss of libido or impotence
- Diabetes symptoms
- Skin hyperpigmentation or blistering
Physical Exam
- Hepatomegaly, splenomegaly
- Skin hyperpigmentation (bronze)
- Hepatic tenderness, jaundice
- Peripheral edema, ascites
- Gynecomastia
- Testicular atrophy
Differential Diagnosis
- Other inflammatory liver diseases
- Alcoholic or biliary cirrhosis
- Repeated transfusions
- Sideroblastic anemia
- Ξ²-thalassemia major
DIAGNOSTIC TESTS & INTERPRETATION
- Serum ferritin (SF): β₯300 Β΅g/L (men, postmenopausal women), β₯200 Β΅g/L (premenopausal women) suspicious.
- Transferrin saturation (TS): β₯45% suspicious, but nonspecific.
- Genetic testing for HFE mutations confirms diagnosis.
- Liver enzymes (ALT, AST), CBC, hematocrit monitor complications.
- Hepatic MRI (T2-weighted) to quantify liver iron if SF >1,000 Β΅g/L, hepatomegaly, or elevated enzymes.
- Liver biopsy if fibrosis staging or uncertain diagnosis needed.
TREATMENT
General Measures
- Phlebotomy (~500 mL/session) weekly or twice weekly initially, may take 2β3 years to deplete iron.
- Maintenance phlebotomy 2β6 times/year to keep SF near 50 Β΅g/L.
- Erythrocytapheresis alternative: removes RBCs only, less frequent treatments needed but costly.
- Hydration before phlebotomy to avoid hypovolemia.
Medications
- Chelation therapy (deferoxamine, deferasirox, deferiprone) for patients unable to undergo phlebotomy.
- Proton pump inhibitors may reduce iron absorption and phlebotomy frequency.
- Testosterone replacement in men may improve hypogonadism symptoms but risk hepatotoxicity.
- Vaccinations: Hepatitis A/B if naive; pneumococcal if cirrhosis present.
ONGOING CARE
- Monitor hemoglobin before phlebotomy; hold if <11 g/dL.
- Check SF every 1β3 months during initiation phase; yearly during maintenance.
- Avoid iron supplements, vitamin C supplements, iron-fortified foods.
- Limit alcohol (<4 units/day) to reduce liver damage risk.
PROGNOSIS
- Dependent on cirrhosis presence.
- Early diagnosis and treatment normalize life expectancy.
- Type 2 juvenile HH presents earlier and more severe.
- Cirrhosis increases risk of hepatocellular carcinoma (~3β4% annual incidence).
- Symptoms like diabetes, hypogonadism may persist despite treatment.
COMPLICATIONS
- Arthritis, chondrocalcinosis
- Osteoporosis
- Diabetes mellitus
- Hypogonadism
- Arrhythmias
- Congestive heart failure
- Cirrhosis (20β45% in C282Y homozygotes with SF >1,000 Β΅g/L)
- Hepatocellular carcinoma risk increased
- Increased susceptibility to infections (Listeria, E. coli, Yersinia, Vibrio)
Clinical Pearls
- Screening recommended in symptomatic or family history patients, not general population.
- Elevated transferrin saturation is earliest marker.
- Ferritin can be falsely elevated in inflammation.
- Hepatic MRI and liver biopsy help evaluate organ damage.
- Phlebotomy remains cornerstone of treatment.
- PPI use may reduce phlebotomy frequency.
- Testosterone replacement requires caution due to hepatotoxicity risk.
References
- Buzzetti E, Kalafateli M, Thorburn D, et al. Interventions for hereditary haemochromatosis: an attempted network meta-analysis. Cochrane Database Syst Rev. 2017;3(3):CD011647.
- Kowdley KV, Brown KE, Ahn J, et al. ACG clinical guideline: hereditary hemochromatosis. Am J Gastroenterol. 2019;114(8):1202-1218.