Going deeper into the subject, I found several moments in which one spoke of genetics and others of genomics. What do I need to do: a genetic examination or genomic examination? After all, WHAT’S THE DIFFERENCE?
Genetics deals with heredity, that is, how individual traits are inherited through genes – on a small scale or molecular scale. The study is done by the investigation of genes, which is the fundamental unit of heredity. Each gene has a specific coding [nucleic acid sequence (DNA / RNA)] that will represent a well-defined function. It is because of him that his hair can be black and with curls, or have blue or brown eyes.
Genomics deals with the study of all (or many) genes in a genome and their interactions with the environment. – wide or very large scale. Although it is related to genetics, they are different, since genetics deals with individual study of genes and what one takes from one generation to another.
Brief summary about what is genetics and genome.
The following videos give a brief summary of what is genetic and genomic (left) and a brief history of the studies of genetics to genomics (right).
How genetic and genomic studies are used for the diagnosis and treatment of cancer
In prostate cancer, for example
- The genetic study – family predisposition may be responsible for 5-10% of all prostate cancers. A family history increases the risk by about 60%.
- Genomics will examine how certain sets of genes in the tumor interact and work. The activity of these genes may then influence the behavior of the tumor, including how rapidly it must grow and spread.
- Genetics may indicate the risk or propensity to develop that type of cancer, while genomics can detect and analyze the genetic variants of that cancer to assist in the choice and course of treatment.
In breast cancer, for example
- Genetics – The known BRCA1 and BRCA2 gene tests help predict cancer risk (ovarian and breast). The genetic test can tell you if you have an abnormal change (also called a mutation) in a gene that is linked to an increased risk of breast cancer.
- Genomic = the known Oncotypoe DX breast cancer assay helps in predicting tumor aggressiveness and in its possible responsiveness to chemotherapy. This test removes a sample of the tumor to see how certain the genes become active. This test then assists in the decision making process. CATEGORIZING BETTER DIAGNOSIS AND DIRECTING THE THERAPEUTICS.
But how is genomics organized normally?
In “regions other than regulatory domains of chromatin” – open or closed “- CHROMOSOMAL TERRITORIES
The less active chromatin in a given cell type or chromosomes containing few genes usually lies well within the nuclear membrane; the more active chromatin (eg, a gene encoding insulin in normal pancreatic cells) and chromosomes carrying many genes, usually occupy the center of the nucleus.
Nuclear location of specific genes correlates with their activity in a given cell.
And how do genes behave?
Within the CHROMOSOMAL TERRITORIES
Genes have more interactions with regions of their own chromosomes; and within any chromosome, more active regions are grouped with other regions also active, while regions less active (silent) or low gene density are grouped with other similar ones.
Long polymers – such as DNA – form very coiled knots without knots, the fractal globule, which can be folded and refolded without disturbing the remainder of the condensed polymer.
Interactions between chromatin on the same chromosome, or between regions with similar properties or functions, are made possible by the way chromatin is organized in the interphase nucleus.
I hope this post has helped to clarify a bit more about the difference between genomics and genetics.
In the future we will talk about the exams that exist for each subject, their differences and prices.
See you in the next posts.