It is now recognized that heritable diseases are due to defective structure or function of specific genes. The knowledge of various developments in genetics can greatly reduce individual human suffering as well as the economic and social costs to the society. Simultaneously, this deluge ofgenetic information also poses several ethical, legal and social dilemmas which must be resolved by broad discussions at the popular level. This is possible only if the common people have the knowledge of at least the basics of this field. This richly illustrated book will be a small but significantstep in this direction. The focus is on thallasaemia, a major inherited disease in India.