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
29 - Friedreich ataxia and cardiomyopathy
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
Friedreich ataxia (OMIM #229300) is characterized by ataxia, cardiomyopathy, and accumulation of iron in mitochondria of the dentate nucleus of the cerebellum and of cardiac myocytes. Systemic iron overload does not occur. This is the most common type of heritable ataxia, and affects approximately 1 person per 30,000.
Clinical manifestations
Initial clinical evidence of Friedreich ataxia usually occurs in adolescents and adults less than 25 years of age. In 115 affected individuals in 90 families, the onset of symptoms occurred at mean age 10.5 years. The symptoms and signs that appear during the first 5 years are ataxia of limbs and trunk, and absence of deep tendon reflexes. As the condtion worsens, additional characteristic findings develop, including dysarthria, hypotonia, scoliosis, a Babinski plantar extensor response, loss of position sense in toes, and loss of vibratory sensation in feet. Peripheral neuropathy adds a sensory component to gait ataxia. Affected individuals experience progressive loss of ability to walk, causing 95% to become chair bound by age 44 years. Pes cavus is common, and is caused by nerve injury and consequent atrophy of intrinsic muscles of the feet.
Hypertrophic cardiomyopathy is present in two-thirds of the patients. This typically affects the interventricular septum or the wall of the left ventricle. In some patients, echocardiography demonstrates cardiac hypertrophy or decreased left ventricular ejection fraction before overt heart failure occurs. Heart failure is the most common cause of death in patients with Friedreich ataxia. Oculomotor abnormalities (nystagmus) develop in some patients.
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- Information
- Handbook of Iron Overload Disorders , pp. 290 - 293Publisher: Cambridge University PressPrint publication year: 2010