genetics versus genomics

genetics is a term that refers to the study of genes and their roles in inheritance – in other words, these are genes that are inherited at birth and passed on from family through generations. every cell in the human body has a complete strand of DNA, and each strand is packed with genes, which carry instructions for certain traits, such as blue eyes, red hair—and even the likelihood of certain cancers –  genetic tests may help identify a person’s risk of cancer and other diseases.

genetics then, is the study of specific and limited numbers of genes, or parts of genes, that have a known function. in biomedical research, scientists try to understand how genes guide the body’s development, cause disease or affect response to drugs. in cancer specifically, genetic testing looks for genetic mutations that may have been inherited through family, and is recommended for anyone with a family history of a certain type of cancer –  those who test positive for BRCA1 gene have a higher risk of developing breast and ovarian cancer. [prognostic biomarker test]

genomics is a more recent term that describes the study of all of a person’s genes [the genome], that includes interactions of those genes with each other and with the person’s environment. genomics, in other words, refers to the study of mutations in genes that may drive various cancer behaviours, from how aggressive it is to whether it spreads to distant locations in the body. each cell in the human body contains tens of thousands of genes, but mutations in just a single gene may cause cells to grow out of control and lead to tumour growth. genomics studies complex diseases such as heart disease, asthma, diabetes, and cancer because these diseases are typically caused more by a combination of genetic and environmental factors than by individual genes. genomics is offering new possibilities for therapies and treatments for some complex diseases, as well as new diagnostic methods. genomics is helping researchers discover why some people get sick from certain infections, environmental factors, and behaviours, while others do not.

genomic testing is used to identify mutations that occur within the cancer itself, these mutations may have occurred due to environmental factors such as sun exposure or tobacco use or from randomly occurring cell division. these mutations can help identify the behaviour of the tumour and help understand why the tumour grows or spreads. genomic testing can allow doctors to match a patient to a targeted therapy for that mutation, an example is BRAF V600E in melanoma or colorectal cancers. [predictive biomarker test]

understanding more about diseases caused by a single gene [using genetics] and complex diseases caused by multiple genes and environmental factors [using genomics] can lead to earlier diagnoses, interventions, and targeted treatments.

source. national human genome research institute