Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder. More than 1,000 genetic tests are currently in use, and more are being developed. Several methods can be used for genetic testing, e.g. the detection of tumors, such as lung cancer, breast cancer,gastric cancer, esophagus cancer, colorectal cancer, pancreatic cancer,cervical cancer, melanoma etc.