Hemochromatosis

Detailed Overview

HH is one of the most common genetic disorders in individuals of Northern European descent. The most prevalent form is caused by a C282Y mutation in the HFE gene, which severely impairs the production of hepcidin, the master iron-regulatory hormone. Because humans lack a physiological pathway to excrete excess iron, the unregulated absorption results in progressive iron accumulation. Decades of iron deposition lead to classic manifestations such as cirrhosis, 'bronze diabetes', and restrictive cardiomyopathy. Early diagnosis is critical because therapeutic phlebotomy can prevent organ damage and restore normal life expectancy.

Epidemiology & Demographics

Incidence/Prevalence: 1 in 200 to 1 in 300 individuals of Northern European (Celtic) ancestry are homozygous for the C282Y mutation. Age distribution: Symptoms typically present in men at 40-50 years and in women at 50-60 years (post-menopause). Gender ratio: Men are affected earlier and more severely than women due to physiological blood loss in women (menstruation, pregnancy).

Etiological Mechanism

Autosomal recessive mutation in the HFE gene located on chromosome 6. The most common genotype is C282Y homozygosity (accounting for 80-90% of clinical HH cases).

Primary Causes

Primary: Homozygous C282Y mutation in the HFE gene, or compound heterozygous C282Y/H63D mutations

Secondary: Non-HFE mutations (e.g., Hemojuvelin, Hepcidin, Transferrin receptor 2) causing juvenile or rarer forms of hemochromatosis

• Genetics: Having two parents who are carriers of the HFE gene mutation.
• Alcohol Consumption: Excessive alcohol intake accelerates liver damage and cirrhosis in patients with HH.
• Gender: Being male significantly increases the risk of clinical organ damage due to lack of physiological blood loss.

In a healthy individual, the liver peptide hepcidin binds to ferroportin (the iron exporter on intestinal enterocytes and macrophages), inducing its internalization and degradation, thereby halting iron absorption into the blood. In HFE-hemochromatosis, the mutated HFE protein fails to complex properly with the transferrin receptor, leading to a false 'low iron' signal to the hepatocytes. Consequently, hepcidin production is drastically reduced. Without hepcidin, ferroportin remains constantly active on the basolateral membrane of enterocytes, resulting in uninhibited iron absorption. Iron saturates circulating transferrin, and non-transferrin-bound iron (NTBI) emerges in the plasma. NTBI is rapidly taken up by parenchymal cells of the liver, pancreas, and heart. Inside these cells, excess iron catalyzes the Fenton reaction, generating highly reactive hydroxyl radicals. This oxidative stress causes lipid peroxidation, DNA damage, and ultimately cell death and fibrosis (e.g., cirrhosis, pancreatic beta-cell destruction).

Characteristic Clinical Presentation

• Severe Fatigue: Profound, unexplained lethargy and weakness; often the earliest symptom.
• Arthralgia: Joint pain, specifically characteristic in the 2nd and 3rd metacarpophalangeal (MCP) joints ('iron fist').
• Erectile Dysfunction/Amenorrhea: Loss of libido and sexual function due to iron deposition in the anterior pituitary causing hypogonadotropic hypogonadism.
• Abdominal Pain: Right upper quadrant discomfort from hepatomegaly.

Physical Examination Signs

• Hepatomegaly (enlarged, firm liver on palpation)
• Skin hyperpigmentation (bronze or slate-gray discoloration, particularly on sun-exposed areas)
• Signs of heart failure (S3 gallop, peripheral edema due to restrictive or dilated cardiomyopathy)
• Testicular atrophy

• Cirrhosis and Hepatocellular Carcinoma (HCC): Patients with HH and cirrhosis have a 20-30% lifetime risk of developing HCC.
• Diabetes Mellitus: Destruction of pancreatic islets leading to insulin-dependent diabetes ('Bronze Diabetes').
• Cardiomyopathy: Arrhythmias and congestive heart failure, which can be fatal if untreated.

Diagnostic Criteria & Guidelines

Initial screening requires fasting Transferrin Saturation (>45%) and elevated Serum Ferritin (>300 ng/mL in men, >200 ng/mL in women). Diagnosis is confirmed by HFE genetic testing revealing C282Y homozygosity. Liver biopsy is reserved for patients with Ferritin > 1000 ng/mL or elevated liver enzymes to assess for cirrhosis.

Differential Diagnosis

• Alcoholic Liver Disease (can also cause elevated ferritin)
• Non-alcoholic Fatty Liver Disease (NAFLD)
• Secondary Iron Overload (e.g., from chronic transfusions for thalassemia)
• Rheumatoid Arthritis (differentiating joint pain)

Laboratory Tests & Biomarkers

• Transferrin Saturation (TSAT): Markedly elevated, often > 50-60% (most sensitive early marker).
• Serum Ferritin: Significantly elevated (e.g., > 1000 ng/mL correlates with high risk of cirrhosis).
• HFE Genotype: Homozygous for C282Y (C282Y/C282Y).
• Liver Function Tests: Mild to moderate elevation in AST and ALT.

Imaging Modalities & Findings

• Hepatic MRI (T2* or R2 MRI):

• Stage 1
  Genetic susceptibility (HFE mutations present) with normal iron parameters and no organ damage.
• Stage 2
  Elevated transferrin saturation and serum ferritin, but clinically asymptomatic without organ dysfunction.
• Stage 3
  Iron overload with early clinical symptoms (lethargy, arthralgia) but without severe organ damage.
• Stage 4
  Advanced disease with irreversible organ damage (cirrhosis, hepatocellular carcinoma, diabetes mellitus, cardiomyopathy).

Second-Line & Adjunctive Therapy

For patients intolerant to phlebotomy (e.g., severe anemia, heart failure): Iron chelation therapy with Deferasirox 10-20 mg/kg/day PO or Deferoxamine SC/IV.

Surgical & Procedural Management

Liver transplantation for decompensated cirrhosis or early-stage Hepatocellular Carcinoma (HCC). Joint replacement (arthroplasty) for severe, debilitating arthropathy.

Recommended Lifestyle Changes

• Strict avoidance of iron supplements and vitamin C supplements (Vitamin C drastically increases intestinal iron absorption)
• Abstinence from alcohol, especially if liver enzymes are elevated or cirrhosis is present
• Avoid eating raw seafood (e.g., oysters) due to the risk of fatal septicemia from Vibrio vulnificus, an iron-loving bacterium

Patient Counseling & Advice

Educate the patient that hemochromatosis is highly manageable and normal life expectancy is expected if treatment begins before cirrhosis develops. Emphasize the necessity of lifelong maintenance phlebotomy. Strongly recommend screening for first-degree relatives (siblings, children) via iron panel and HFE genetic testing.

Follow-Up & Monitoring Schedule

Check Hemoglobin and Ferritin prior to every phlebotomy during induction. Once at maintenance, monitor Ferritin every 3-6 months. For patients with cirrhosis, routine HCC screening with hepatic ultrasound and AFP every 6 months is mandatory.

Preventive Strategies

Primary prevention involves genetic screening of first-degree relatives to initiate phlebotomy before iron loading damages organs.

Normal life expectancy if phlebotomy is initiated before the onset of cirrhosis or diabetes. If cirrhosis is present at diagnosis, life expectancy is reduced and HCC risk is high.