1 The Chondrodystrophies.- Classification of the Chondrodystrophies.- Evaluation of the Dwarfed Patient.- Clinical, Radiographic, Genetic, and Pathological Features of the Chondrodystrophies.- Animal Models of the Chondrodystrophies.- Future Trends in Chondrodystrophy Research.- 2 New Techniques in the Study of Human Chromosomes: Methods and Applications.- Fluorescence Microscopy.- Giemsa Staining.- The Usage of Banding Techniques.- Abnormalities Detected by Banding Analysis.- Chemical Properties of the Bands.- Technical Appendix.- 3 The Thalassemias: Models for Analysis of Quantitative Gene Control.- History.- Definition.- Organization of Globin Genes.- Ontogeny of Hemoglobin Production.- Inheritance of Thalassemia.- Frequency of Thalassemia.- Regulation of Hemoglobin Synthesis and Turnover.- Transcription of Hemoglobin Genes.- Intranuclear Processing of the Primary Gene Product.- Transport of Messenger RNA to the Cytoplasm.- Cytoplasmic Metabolism of Messenger RNA.- Balance of Hemin and Globin (Protein) Synthesis in Reticulocytes.- Other Steps in Hemoglobin Synthesis and Degradation.- Pathophysiology of the Thalassemias.- Directions in Therapy.- Note Added in Proof.- 4 Spontaneous Mutation in Man.- “Classical” Mutation Rates.- Molecular Aspects of Human Mutation.- Spontaneous Mutation in Other Organisms and Its Significance for the Understanding of Human Mutations.- 5 Genetic Screening Legislation.- The Public Health Power.- Legislation Mandating Detection of Genetic Disease.- Legislation Mandating Screening for Genetic Traits.- Future of State-Supported Genetic Screening.