1 Biochemistry and Genetics of the ABO, Lewis, and P Blood Group Systems.- The ABO System.- Serology and Genetics.- Chemistry of A, B, and H Substances.- Relationship between the A, B, and H Determinant Structures and the Blood Group Genes.- Glycosyltransferase Products of the H, A, and B Genes.- The Lewis System.- Serology and Genetics.- Chemistry of Lewis Substances.- Biosynthesis of Lea and Leb Determinants.- “Lewis-like” Structures and the ?-3-L-Fucosyltransferase.- The Antigens “Lec” and “Led”.- Interrelationships between ABH and Le Gene Products.- The Lewis System and Renal Transplantation.- The P System.- Serology and Genetics.- Chemistry of P1, P, and Pk Determinants.- Biosynthetic Pathways.- Relationship between ABH and P Systems.- Concluding Remarks.- References.- 2 HLA—A Central Immunological Agency of Man.- HLA: A Supergene.- HLA Terminology.- Inheritance of HLA.- Recombination.- The HLA-A, -B, and -C Allelic Series of Antigens.- Typing Procedures.- Antibodies.- HLA Serology.- The Use of Multispecific Sera.- Tissue Distribution.- Biochemistry.- HLA-D.- Homozygous HLA-D Stimulator Cells and MLR Typing.- Tissue Distribution.- Primed Lymphocyte Typing (PLT).- Cell-Mediated Lympholysis (CML).- HLA-DR.- HLA-DR Typing.- Tissue Distribution.- Serology.- Biochemistry.- Population Genetics.- The HLA “Supergene” and Transplantation.- Evolution and Maintenance of the MHC—Function?.- What of the Future?.- References.- 3 Linkage Analysis in Man.- General Considerations.- Approaches to Gene Mapping.- Linkage and Synteny.- Crossing-Over, Recombination, and Genetic Map Distance.- Coincidence and Interference.- Linkage vs. Association.- Historical Perspective.- Linkage in Nonhumans.- Linkage in Man.- Approach to Family Studies.- Framework of Family-Based Linkage Studies.- Mappable Loci.- Main vs. Test Locus.- Efficiency and Power in Linkage Studies.- Preparation of Data Prior to Analysis.- Consistency Checking.- Segregation Analysis.- Age-Dependent Penetrance.- Analysis of Data.- Mendelian Traits.- Quantitative Traits.- Interpretation of Results.- Sex Differences in Recombination.- Acceptance and Significance of Linkage.- Confidence Intervals.- Prior Probability of Linkage.- Linkage Heterogeneity.- Age and Recombination.- Mapping Functions.- Multipoint Mapping.- Significance of Linkage.- References.- 4 Sister Chromatid Exchanges.- BrdUrd Methodology for SCE Detection.- Basic Information about SCEs.- Induction of Sister Chromatid Exchange by Clastogens.- Extension of SCE Studies from in Vitro to in Vivo Systems.- Interpretation of SCE Induction Tests.- Relationship of SCE Induction to DNA Damage, Repair, and Synthesis.- Relationship of SCE Induction to Mutagenesis.- Sister Chromatid Differentiation in Meiotic Cells.- Sister Chromatid Exchange Formation in Heritable Human Diseases.- Studies of the Mechanism of SCE Formation.- References.- 5 Genetic Disorders of Male Sexual Differentiation.- Normal Male Sex Differentiation in the Fetus.- The Neutral Stage.- Differentiation of the Fetal Testes.- Functions of the Fetal Testes.- Gonadotropin Regulation.- Function of Androgen Target Cells.- Androgen-Mediated Effects in the Fetus.- Abnormal Male Sex Differentiation.- Genetic Considerations.- Chromosomal Abnormalities.- Male Differentiation Associated with Inappropriate Karyotype (XX Males).- True Hermaphroditism.- Male Pseudohermaphroditism.- References.- Addenda.