Abstract
The growth of medical cytogenetics during the past 25 years has shown that the medical significance of the human chromosomal diseases vary with their frequency. This growth depended on the development and application of newer cytogenetic techniques such as autoradiography and various banding techniques, which permitted the detection of more subtle chromosomal abnormalities within individual chromosomes such as deletions, inversions and duplications, which by conventional staining techniques looked normal. The future of medical cytogenetics may lie in genetic engineering, screening the environment for carcinogens and a better understanding of the nature of the aging process.