1 The Pi Polymorphism: Genetic, Biochemical, and Clinical Aspects of Human ?1-Antitrypsin.- Historical Review.- Pi Variants.- Biochemical Aspects.- Metabolism of ?1-Antitrypsin.- Association between Pi Types and Disease.- Protease Inhibitor Systems and Disease Mechanisms.- Unresolved Problems.- References.- 2 Segregation Analysis.- Mathematical Formulation of Genetic Models.- The Likelihood Method.- Examples of Segregation Analysis.- Conclusion.- Appendix: Notes on Computational Methods.- References.- 3 Genetic, Metabolic, and Biochemical Aspects of the Porphyrias.- Tetrapyrroles.- Enzymes and Intermediates of the Heme Biosynthetic Pathway.- Regulation of Enzymes of Heme Biosynthesis.- Classification of the Human Porphyrias.- References.- 4 The Molecular Genetics of Thalassemia.- The New Genetics.- The Nature of Thalassemias.- DNA Polymorphisms in the ?-like Globin Gene Cluster.- Prenatal Diagnosis of Hemoglobin Disorders by DNA Analysis.- Additional Approaches to the Correlation of Gene Structure and Function.- Summary and Conclusions.- References.- 5 Advances in the Treatment of Inherited Metabolic Diseases.- Metabolic Manipulation.- Gene Product Therapy.- Enzyme Replacement Therapy.- Gene Therapy.- References.- Addenda.