Genetics and Genetic Disorders

Cancer Genetics

From the time Boveri observed that chromosomal changes are a feature of cancer, it has been thought to be a disease caused primarily by alterations in the genome of the affected cells. Today, the notion of cancer being a consequence of genetic alterations, is almost intuitive and the advances in molecular biology and genomics have given us many tools to understand and possibly to combat cancer. Since science has always existed in a continuum, the genetic alterations in cancer have to be understood in the context of cellular organization, differentiation, tissue organization host response and susceptibility angiogenesis etc. The properties that are taken to typify cancer cells are also present in normal cells. These include cell division, migration and even invasion. However what marks out cancer cells is dysregulation and inappropriate expression of these attributes. Typically the genetic alterations in cancer can be said to include three major types of genes, oncogenes, tumour suppressor genes and genes that preserve the integrity of the genome. It must be kept in mind that cancer is a multi-step process and several genetic alterations are required for a full blown cancer phenotype.