Book contents
- Frontmatter
- Contents
- Foreword by Anthony S. Tavill
- Preface
- 1 History of iron overload disorders
- 2 Normal iron absorption and metabolism
- 3 Iron toxicity
- 4 Tests for hemochromatosis and iron overload
- 5 Complications of hemochromatosis and iron overload
- 6 Insulin resistance and iron overload
- 7 Infections and immunity
- 8 Classical and atypical HFE hemochromatosis
- 9 Heterozygosity for HFE C282Y
- 10 Porphyria cutanea tarda
- 11 Mitochondrial mutations as modifiers of hemochromatosis
- 12 Hemochromatosis associated with ferroportin gene (SLC40A1) mutations
- 13 Hemochromatosis associated with hemojuvelin gene (HJV) mutations
- 14 Hemochromatosis associated with hepcidin gene (HAMP) mutations
- 15 Hemochromatosis associated with transferrin receptor-2 gene (TFR2) mutations
- 16 Iron overload associated with IRE mutation of ferritin heavy-chain gene (FTH1)
- 17 Hereditary hyperferritinemia-cataract syndrome: IRE mutations of ferritin light-chain gene (FTL)
- 18 Iron overload in Native Africans and African-Americans
- 19 Hereditary atransferrinemia
- 20 Divalent metal transporter-1 (SLC11A2) iron overload
- 21 Iron overload associated with thalassemia syndromes
- 22 Iron overload associated with hemoglobinopathies
- 23 Iron overload associated with pyruvate kinase deficiency
- 24 Iron overload associated with congenital dyserythropoietic anemias
- 25 Hereditary sideroblastic anemias
- 26 Pearson marrow–pancreas syndrome
- 27 Acquired sideroblastic anemias
- 28 Hereditary aceruloplasminemia
- 29 Friedreich ataxia and cardiomyopathy
- 30 Pantothenate kinase (PANK2)-associated neurodegeneration
- 31 Neuroferritinopathies
- 32 GRACILE syndrome
- 33 Neonatal hemochromatosis
- 34 Iron overload due to excessive supplementation
- 35 Localized iron overload
- 36 Management of iron overload
- 37 Population screening for hemochromatosis
- 38 Ethical, legal, and social implications
- 39 Directions for future research
- Index
- Plate section
- References
9 - Heterozygosity for HFE C282Y
Published online by Cambridge University Press: 01 June 2011
- Frontmatter
- Contents
- Foreword by Anthony S. Tavill
- Preface
- 1 History of iron overload disorders
- 2 Normal iron absorption and metabolism
- 3 Iron toxicity
- 4 Tests for hemochromatosis and iron overload
- 5 Complications of hemochromatosis and iron overload
- 6 Insulin resistance and iron overload
- 7 Infections and immunity
- 8 Classical and atypical HFE hemochromatosis
- 9 Heterozygosity for HFE C282Y
- 10 Porphyria cutanea tarda
- 11 Mitochondrial mutations as modifiers of hemochromatosis
- 12 Hemochromatosis associated with ferroportin gene (SLC40A1) mutations
- 13 Hemochromatosis associated with hemojuvelin gene (HJV) mutations
- 14 Hemochromatosis associated with hepcidin gene (HAMP) mutations
- 15 Hemochromatosis associated with transferrin receptor-2 gene (TFR2) mutations
- 16 Iron overload associated with IRE mutation of ferritin heavy-chain gene (FTH1)
- 17 Hereditary hyperferritinemia-cataract syndrome: IRE mutations of ferritin light-chain gene (FTL)
- 18 Iron overload in Native Africans and African-Americans
- 19 Hereditary atransferrinemia
- 20 Divalent metal transporter-1 (SLC11A2) iron overload
- 21 Iron overload associated with thalassemia syndromes
- 22 Iron overload associated with hemoglobinopathies
- 23 Iron overload associated with pyruvate kinase deficiency
- 24 Iron overload associated with congenital dyserythropoietic anemias
- 25 Hereditary sideroblastic anemias
- 26 Pearson marrow–pancreas syndrome
- 27 Acquired sideroblastic anemias
- 28 Hereditary aceruloplasminemia
- 29 Friedreich ataxia and cardiomyopathy
- 30 Pantothenate kinase (PANK2)-associated neurodegeneration
- 31 Neuroferritinopathies
- 32 GRACILE syndrome
- 33 Neonatal hemochromatosis
- 34 Iron overload due to excessive supplementation
- 35 Localized iron overload
- 36 Management of iron overload
- 37 Population screening for hemochromatosis
- 38 Ethical, legal, and social implications
- 39 Directions for future research
- Index
- Plate section
- References
Summary
The C282Y polymorphism of the HFE gene on chromosome 6p21.3 is the most common known human mutation that has a marked effect on iron absorption and homeostasis. Approximately 12% of Caucasians of northern or western European descent living in Europe or in derivative countries such as the US, Canada, Australia, or New Zealand are simple heterozygotes for C282Y, and they outnumber C282Y homozygotes in these populations by approximately 25:1. In the US alone, approximately 20 million whites are C282Y heterozygotes. If iron-related organ injury or another deleterious allele on C282Y-bearing chromosome 6p haplotypes were to occur in C282Y heterozygotes, the number of individuals at potential risk is great. This has led to an interest in defining: (a) the iron phenotype and any related iron or liver morbidity of C282Y heterozygotes and their management; (b) the optimal means to identify C282Y heterozygotes and to estimate their prevalence in populations; and (c) the association of C282Y with various non-iron-related disorders.
History
The HFE C282Y mutation arose in northwestern Europe, perhaps in the Neolithic Age. The original C282Y mutation probably occurred on a chromosome 6 haplotype characterized by human leukocyte antigens (HLA)-A*03, B*07, and by the marker allele D6S105(8). C282Y spread with various population movements, especially Viking migrations. Many C282Y homozygotes alive today have one or two copies of the ancestral haplotype. Likewise, all C282Y heterozygotes have inherited a common HFE polymorphism, but also much or all of an ancestral chromosome with its other component genes and alleles, the effects of which must be considered in understanding fully the effects of C282Y heterozygosity.
- Type
- Chapter
- Information
- Handbook of Iron Overload Disorders , pp. 149 - 159Publisher: Cambridge University PressPrint publication year: 2010