Introduction: Social Attitude towards Disabled People in Different Areas and Cultures -- Role of Ethics Committees -- International Quality Control in the Field of Diagnostics -- Structural Chromosom Abarrations -- Mutations in Non-coding DNA Regions. Single Case Presentations of Intrachromosomal Rearrangements: Inversions -- Deletions -- Duplications -- Ring Chromosomes -- Isochromosomes. Single Case Presentations of Interchromosomal Rearrangements: Translocations -- Insertions -- Complex Chromosome Rearrangements (CCR) -- Marker Chromosomes -- Cases of Intra- and Interchromosomal Mutation in Polymorphic Regions. Guidelines to Clinical Questions and Practical Approaches: Genetic Counselling Procedures -- Life of Persons with Chromosomal Disorders -- Support Groups for Chromosomal Disorders -- Diagnosis and Therapy -- Outlook.