1. Genes and Metabolic Liver Disease: Hemochromatosis
Bruce R. Bacon, M.D.
James F. King M.D. Endowed Chair in Gastroenterology
Professor of Internal Medicine
Division of Gastroenterology and Hepatology
Saint Louis University Liver Center
St. Louis, Missouri

2. History of Hemochromatosis
1865 – Trosier – first case
1889 – von Recklinghausen – hemochromatosis
1935 – Sheldon – inherited defect in iron metabolism
1976 – Simon – HLA-A3, short arm chromosome 6
1996 – Mecator Genetics – HFE
1997 – present
DMT-1
Ferroportin
Transferrin receptor-2
Hemojuvelin
Hepcidin

3. Classification of Inherited Iron Overload Syndromes
Hereditary Hemochromatosis
HFE-related
C282Y/C282Y
C282Y/H63D
Other HFE mutations
Non-HFE-related
Hemojuvelin (HJV)
Transferrin receptor-2 (TfR-2)
Ferroportin (SLC40A1)
Hepcidin (HAMP)
African iron overload

4. Classification of Iron Overload Syndromes - 2
Secondary Iron Overload
Iron-loading anemias
Thalassemia major
Sideroblastic
Chronic hemolytic anemia
Aplastic anemia
Pyruvate kinase deficiency
Pyridoxine-responsive anemia
Parenteral iron overload
Red blood cell transfusions
Iron-dextran injections
Long-term hemodialysis
Chronic liver disease
Porphyria cutanea tarda
Hepatitis C
Hepatitis B
Alcoholic liver disease
Nonalcoholic steatohepatitis
Following portocaval shunt
Dysmetabolic iron overload syndrome
Miscellaneous
Neonatal iron overload
Aceruloplasminemia
Congenital atransferrinemia

5. HFE Genotype in Patients with Hemochromatosis
Study
Feder,
et al.
Beutler,
et al
Jouanolle,
Jazwinksa,
Carella,
Adams and
Chakrabarti
Bacon,
Country
USA
France
Australia
Italy
Canada
No. of Patients
178
147 65
112* 75
128 66
Genotype n(%)
C282Y
148 (83)
121 (82)
59 (91)
112 (100)
48 (64)
122 (95)
60 (91)
C282Y**
H63D
8 (4)
8 (5)
3 (5)
2 (2.27)
2 (1.6)
1 (1.5)
Wild Type
1 (0.5)
2 (1)
1 (1.3)
Wild type
7 (4)
4 (3)
2 (3)
3 (4)
13 (7)
10 (7)
16 (21)
4 (3.1)
*All patients had a family history of iron overload
** Compound heterozygote

6. Ser65  Cys, S65C His63  Asp, H63D  Heavy Chain 1 2
Cys282  Tyr, C282Y
 Heavy Chain
Ser65  Cys, S65C 1 2
NH2
2-microglobulin
Extracellular
HOOC
Plasma membrane
Cytosol 3
Nature Genetics 13: , 1996

7. HFE Genotype in Patients with Hemochromatosis
771 patients with phenotypic HH
670 (86.9%) with C282Y/C282Y
44 (5.7%) with C282Y/H63D
24 (3.1%) with C282Y/wt

8. Incidence of Hereditary Hemochromatosis
1 in individuals of Northern European descent
11% heterozygotes
Estimated 600,000 to 1,000,000 afflicted Americans
Estimated 27 million heterozygotes

9. Hereditary Hemochromatosis - Diagnosis
Requirements of Diagnosis
Suspicion, serum iron studies
Liver biopsy
Use of HII
Differential diagnosis
Alcoholic liver disease
Chronic viral hepatitis
Nonalcoholic steatohepatitis
Genetic test

10. Typical Symptoms in Patients with HH%
Weakness, lethargy, fatigue
40-85
Apathy, lack of interest
Abdominal pain
30-60
Weight loss
Arthralgias
40-60
Loss of libido, impotence
Amenorrhea
20-60
Congestive heart failure symptoms
0-40

11. Common Physical Findings in HH%
Hepatomegaly
60-85
Cirrhosis
50-95
Skin pigmentation
40-80
Arthritis (second, third metacarpophalaneal joints)
40-60
Clinical diabetes
10-60
Splenomegaly
10-40
Loss of body hair
10-30
Testicular atrophy
Dilated cardiomyopathy
0-30

12. Hereditary Hemochromatosis
Symptoms and Physical Findings (%)
No symptoms 73
Lethargy, and/or weakness 25
Loss of libido, impotence 12
Arthralgias 13
Diabetes 5
Skin pigmentation
Am J Gastroenterol 92: , 1997

13. Principal Clinical Features in Hereditary Hemochromatosis
Milder
et al.
1980
Edwards
Niederau
1985
Adams
1991
Bacon & Sadiq
1997
Number of subjects
34†
35*
163*
37‡ 40
Symptoms (#)
Weakness, lethargy 73 20 83 19 25
Abdominal pain 50 23 58 3
Arthralgias 47 57 43 13
Loss of libido, impotence 56 29 38 32 12
Cardiac failure symptoms 35 15
Physical and Diagnostic Findings (%)
Cirrhosis (biopsy) 94 69
Hepatomegaly 76 54
Splenomegaly -
Loss of body hair 6
Gynecomastia 8
Testicular atrophy 14
Skin pigmentation 82 75 9 5
Clinical diabetes 53 55 11
* Patient selection occurred by both clinical features and family screening.
† Only symptomatic index cases were studied. ‡ Discovered by family studies.
Zakim Boyer, 1996;1453.

14. Evaluation of Iron Stores
Serum iron, TF saturation and ferritin
Liver biopsy for stainable iron, biochemical determination of iron
Noninvasive imaging modalities
Computed tomography
Magnetic resonance imaging
Magnetic susceptibility
Iron removed by phlebotomy (1 U=250 mg)

15. Blood Iron Studies in HH
Normal HH
Serum iron (µg/dl)
50-150
Transferrin (mg/dl)
Transferrin saturation (%)
20-50
80-100
Serum ferritin (ng/ml)
Males
20-300
500-6,000
Females
15-250

16. Hemochromatosis – Role of Liver Biopsy
In the past – establish diagnosis
Determine degree of fibrosis, cirrhosis
Determine other abnormalities
Phenotypic variability
Recommended if:
Ferritin > 1000 ng/mL
ALT, AST elevated
Hepatomegaly
Age > 40 years

22. Therapeutic Phlebotomy for HH
Clearly improves survival
Prepare patients for up to 6 – 12 months
Iron burden in men greater than in women despite initial HIC
Difficult to predict phlebotomy requirements
Each unit of blood – approximately 30 ng/mL ferritin

23. Therapeutic Phlebotomy for HH
Weekly phlebotomy
Hct. > 35% before each one
Ferritin to 50 to 100 ng/mL
Transferrin saturation to < 50%

24. Maintenance Phlebotomy for HH
Most patients – one unit Q 2-3 months
TS < 50%; ferritin < 100 ng/mL
One unit of whole blood = 250 mg iron
Most patients absorb 2 to 3 mg/day, more than needed
Some patients – no re-accumulation

25. Hereditary Hemochromatosis Response to Therapy
Edwards et al. Ann Int Med 93: , 1980

26. Results of Therapy Reduction to normal tissue iron stores.
Improved survival if diagnosis and treatment before development of cirrhosis and diabetes.
Improved sense of well-being, energy level.
Improved cardiac function.
Improved control of diabetes.
Reduction in abdominal pain.
Reduction in skin pigmentation.
Normalization of elevated liver enzymes.
Reversal of hepatic fibrosis (approximately 30% of cases).
No reversal of established cirrhosis.
Reduction in portal hypertension in cirrhotics.
No (or minimal) improvement in arthropathy.
No reversal of testicular atrophy.

27. Hereditary Hemochromatosis: Survival
N Engl J Med 313: , 1985

28. Hereditary Hemochromatosis: Survival with Cirrhosis
N Engl J Med 313: , 1985

29. HH – Family Screening HFE mutation analysis has replaced HLA-typing
Practically – HFE mutation analysis, TS, and ferritin all at once

30. HH – Family Screening
For analysis of risk in children – perform mutation analysis in spouse (or other parent) first
May be able to avoid testing in children
Adams, Clin Genet 53: , 1998

31. General Population Studies in HH
Transferrin saturation, ferritin, CBC
HFE mutation analysis
Several studies from around the world

32. Population Screening for Hemochromatosis
41,038 adults screened in San Diego
Health appraisal unit
CBC, transferrin saturation, ferritin level, HFE genotype
Questionnaire
Beutler et al., Lancet 359: , 2002

33. Population Screening for Hemochromatosis
152 C282Y/C282Y
616 C282Y/H63D
67% of C282Y/C282Y had elevated ferritin
No difference in symptoms from controls
1 of 152 with signs and symptoms of hemochromatosis
Beutler et al., Lancet 359: , 2002

34. Population Screening for Hemochromatosis
Beutler et al., Lancet 359: , 2002

35. Prevalence of homozygotes C282Y homozygotes with a normal ferritin (%)
Prevalence of C282Y Homozygotes Without Iron Overload in Screening Studies
Population sample
Country n
Prevalence of homozygotes
C282Y homozygotes with a normal ferritin (%)
Electoral roll
New Zealand
1,064
1 in 213 40
Primary care
USA
1,653
1 in 276 50
Epidemiological survey
Australia
3,011
1 in 188 25
Blood donors
Canada
4,211
1 in 327 81
General public
41,038
1 in 270 33
North America
44,082
1 in 227
29,676
1 in 146 32
Total
124,636
1 in 240 41

36. Hereditary Hemochromatosis
Patients with C282Y/C282Y mutation without iron overload
Environmental factors
Nutritional deficiency, malabsorption
Gastrointestinal blood loss
Menstrual blood loss
Pregnancy
Genetic factors
Hepcidin
DMT-1
Ferroportin
TfR-2
Hemojuvelin
Others

37. Hereditary Hemochromatosis
Patients with iron overload
10% to 15% are negative for C282Y/C282Y
Mutations in other genes
Ferroportin
TfR-2
Hepcidin
Hemojuvelin
Others

38. Iron Overload Syndromes
Ferroportin (SLC40A1)
2q32
Autosomal dominant
RE cell distribution
African iron overload, Solomon Islanders
Pedigree described
Pietrangelo et al., NEJM 341: , 1999
Montosi et al., JCI 108: , 2001
Gordeuk et al., Blood Cells Mol Dis 31: , 2003

39. Iron Overload Syndromes
Transferrin receptor-2 (TfR-2)
7q22
Autosomal recessive
Parenchymal cell distribution
Pedigree described
Hoffman et al., Blood 100: , 2002

40. Iron Overload Syndromes
Hepcidin (HAMP)
19q13.1
25 amino-acid peptide
Juvenile iron overload (rarely)
Autosomal recessive
Parenchymal cell distribution
More importantly – principal “hormone” involved in iron regulation
Roetto et al., Nat Genet 33:21-22, 2003

41. Iron Overload Syndromes
Hemojuvelin (HJV)
1q21
Juvenile iron overload
Autosomal recessive
Parenchymal cell distribution
Pedigree described
Fleming and Bacon, NEJM 352: , 2005

42. Hereditary Hemochromatosis
Genetic testing for non-HFE HH
InVitae, San Francisco Genetic Testing Company
HFE
HAMP – hepcidin
HFE-2 – hemojuvelin
SLC40A1 – ferroportin
TFR2
$1500 per order, 2 weeks

43. Hereditary Hemochromatosis
Summary
In 2013…
Most patients with hemochromatosis do not need a liver biopsy
Only about 60% of C282Y homozygous patients have phenotypic expression
About 25% of C282Y homozygous men have signs or symptoms of hemochromatosis
Detailed gene testing available