In the past few decades, we’ve made large strides in our understanding of genes and how they affect our health.

In the middle of the 20th century, we started to understand that DNA carries the complete instructions on how a human develops. Not only are scientists now studying how certain genes may be related to diseases, but also they’re learning how complex relationships between genes and the environment can lead to increased risk of certain diseases.

Genomics is an important tool in this research. It goes a step beyond a simple genetic understanding. But what is genomics, and how does it differ from genetics?

To understand what genomics is, you first need to have a firm grasp on genetics. People first started using the word “gene” in 1908, which was before the discovery of DNA. Some characteristics and disease risks occur in connection with a single gene or region of DNA. Genetics focuses on those individual genes and how they influence health and disease.

Genes consist of several thousand base pairs, which are combinations of the four nucleic acids:

  • adenosine
  • thymine
  • guanine
  • cytosine

Genes contain everything needed to make proteins. Their unique pattern creates the ultimate design of protein it’s meant to create. These proteins are what perform all of your body’s processes.

According to the National Human Genome Research Institute (NHGRI), humans have up to 25,000 genes. Three billion base pairs make up our entire DNA. The NHGRI states that every cell in our bodies has a complete copy of the approximately three billion DNA base pairs that make up the human genome.

The study of genetics led to the identification of thousands of genes that play a role in disease. Although some genes have subtle effects that scientists don’t fully understand, other gene patterns are responsible for diseases catastrophic to human health.

Some examples of single-gene diseases include:

  • sickle-cell anemia
  • cystic fibrosis
  • Huntington’s disease
  • hemophilia A

Single genes can also mutate during your lifespan, which may cause a range of effects, including having no effect to potentially leading to cancer. Genetics helps us understand how genes influence the growth of cancer cells. The National Cancer Institutealso notes that genetics has also shown us how inherited genes, like the BRCA1 and BRCA2 genes, can predispose some people to develop cancer mutations.

Thousands of single-gene inherited diseases exist, but scientists don’t understand the significance of all of them well. For example, scientists may identify a section of DNA that occurs in those with a certain disease. However, it takes time to understand what that gene does and which proteins the gene makes or controls. Knowing what a gene does allows scientists to develop better understanding and treatments for the disease.

New techniques are evolving to allow geneticists to understand the link between genes and the molecules that lead to disease. One of those tools is genomics. Genomics is the study of not just single genes, but the entire set of genes, known as the genome.

The Human Genome Project was a project to create a dictionary containing every gene in a human. The Human Genome Project was completed in 2003. It made available a set of three billion base pairs for a generic human. In 2005, a map of all the different variations seen in humans was published. Currently, researchers continue to determine what the variations mean.

The availability of the entire genome of humans and several other species allows researchers to study genes in new ways. It’s now easier to understand how genes interact with each other and with the environment.

Looking at the entire set of genes allows us to understand subtler relationships. Instead of only understanding single-gene diseases, such as sickle cell anemia or cystic fibrosis, we can study complex illnesses such as heart disease, diabetes, and cancer. It’s possible to conduct medical studies to look at the impact of environmental factors, including diet, exercise, and chemical exposure, on genes.

With the information gained from genomic studies, scientists can identify people who are more likely to have certain diseases. This knowledge then allows us to work on preventing the onset of disease in those people. It can also help with family planning and genetic counseling if certain diseases are more common in your family.

One of the most promising research areas in genomics is pharmacogenomics. This is the study of how different people react to different medications.

Due to genetic variations between individuals, some people can’t take certain medications. Sometimes, differences in how the body metabolizes, or processes, a drug means that only certain people can successfully take that drug. A variation can exist in how different individuals are affected due to genetic differences.

In the past, large differences in the safety and efficacy of a drug prevented that drug from being approved for use. Some very effective drugs for a certain population haven’t been made available to the public because of this problem. However, for some medications, genetic tests are now able to approximate how a specific drug affects a person. This leads to more successful treatment and the reduction of adverse drug reactions. However, this is not commonly in use for most medications.

Genomics is also looking at the complete gene set of:

  • cells
  • viruses
  • bacteria
  • parasites

More knowledge about potential enemies of human health will help researchers devise better ways to attack something harming the body.

It’s becoming easier to read, or sequence, large amounts of DNA. Soon, it will be a relatively cheap and quick process to sequence any individual’s genome. Scientists are still working out the ethical and legal implications of genomics and genetic testing.

This kind of sensitive information must be protected. Your genome is the most intensely personal information that exists. Still, knowledge about your genome helps prevent disease and makes treatment more effective.