Genetics of Cancers

Abstract Medical Genetics as a bridge between basic sciences and clinical studies has exponentially grown over recent decades with a major focus on the molecular basis of diseases. On the other hand, although modernization has solved many problems in human life, there are significant health issues which need more working than before. Cancer is one of the greatest issues in medicine. It is a major cause of early mortality and morbidity with a high burden on health economy. Cancer is named as a genetic disease that can be inherited sometimes. It can be classified to sporadic and familial forms. Epidemiological and family and twin studies helped a lot to understand different risk factors in cancer initiation, progress, invasion and metastasis. Carcinogenesis is a multistage process involved by series of mutant genes. In this talk, a review will be provided on genes related to tumorgenesis in three classes; oncogenes, tumor suppressor genes and mismatch repair genes as well as cytogenetics overview in cancer. The causes of cancer are mainly classified in two components: environmental and genetic factors. Sporadic common cancers have complex and multifactorial etiologies. In contrast, familial cancer syndromes are rare with a simple genetic inheritance. They have Mendelian patterns and genetic counseling will help high risk families in management of their diseases in case of early diagnosis, treatment, surveillance and prognosis. This talk attempts to discuss overview of management, types of genes cause common familial cancer syndromes, their genotype-phenotype correlations and what other factors are important in cancer genetic counseling. What are our strengths and weakness in approach to cancer genetics will be highlighted as well as what should be done in Iran. It can be concluded that co-operation of basic and clinical sciences can discuss the interaction of different components in generating cancer and will hopefully provide early diagnosis and prevention of cancer in future.