Genomics is a study for describing the development of genome-scale technologies and their application to all areas of biological investigation.
The genome is the entire DNA content that is present within one cell of an organism. Experts in genomics strive to determine complete DNA sequences and perform genetic mapping to help understand disease.
Genomics also involves the study of intragenomic processes such as epistasis, heterosis and pleiotropy. The fields of molecular biology and genetics are mainly concerned with the study of the role and function of single genes, a major topic in today’s biomedical research. By contrast, genomics does not involve single gene research unless the purpose is to understand a single gene’s effects in context of the entire genome.
The genome is a store of biological information but on its own it is unable to release that information to the cell. Utilization of the biological information contained in the genome requires the coordinated activity of enzymes and other proteins, which participate in a complex series of biochemical reactions referred to as genome expression. The initial product of genome expression is the transcriptome, a collection of RNA molecules derived from those protein-coding genes whose biological information is required by the cell at a particular time.
The human genome, which is typical of the genomes of all multicellular animals, consists of two distinct parts –
- The nuclear genome comprises approximately 3,200,000,000 nucleotides of DNA, divided into 24 linear molecules, the shortest 50,000,000 nucleotides in length and the longest 260,000,000 nucleotides, each contained in a different chromosome. These 24 chromosomes consist of 22 autosomes and the two sex chromosomes, X and Y. Altogether, some 35,000 genes are present in the human nuclear genome.
- The mitochondrial genome is a circular DNA molecule of 16,569 nucleotides, multiple copies of which are located in the energy-generating organelles called mitochondria. The human mitochondrial genome contains just 37 genes.
Genomics is a concept that was first developed by Fred Sanger who first sequenced the complete genome of a virus and of a mitochondrion. He initiated the practice of sequencing and genome mapping as well as developing bioinformatics and data storage in the 1970s and 1980s.
Genetic Information
Information about the genome (DNA), which includes –
- Family health history
- Diseases and risks of health problems that run in the family
- Family stories
How is Genomic Helpful?
- Genomics has the potential of offering new therapeutic methods for the treatment of some diseases, as well as new diagnostic methods.
- Major tools and methods related to genomics are bioinformatics, genetic analysis, measurement of gene expression, and determination of gene function.
- Genomics helps researchers discover why some people get sick from certain infections, environmental factors, and behaviors, while others do not. For example, there are some people who exercise their whole lives, eat a healthy diet, have regular medical checkups, and die of a heart attack at age 40. There are also people who smoke, never exercise, eat unhealthy foods and live to be 100. Genomics may hold the key to understanding these differences.
- Genomics helps in 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. A person’s health is influenced by his/her family history and shared environmental factors. This makes family history an important, personalized tool that can help identify many of the causative factors for conditions that also have a genetic component. The family history can serve as the cornerstone for learning about genetic and genomic conditions in a family, and for developing individualized approaches to disease prevention, intervention, and treatment.
- Genomics plays a part in nine of the ten Leading causes of death in the United States. All human beings are 99.9 percent identical in genetic makeup, but differences in the remaining 0.1 percent may hold important clues about the causes of disease.
Personalized Genomic Medicine
Personalized genomic medicine is a way to improve a person’s health using his/her family history, medical history, genetic information, and lifestyle. The features of PGM include –
- Personalized – Risks uniquely depends on the person
- Predictive – Predicts the chances of developing certain disorders
- Preventive – Based on genetic test results and specific lifestyle behaviors, offers healthy solutions to decrease disease risk
- Participatory – Requires the person’s involvement
The role of genomics in healthcare is like a tip of the iceberg and is expected to develop more in coming years.